Low-Carb Mexican Chicken Soup, Made Weeknight-Easy

This low-carb Mexican chicken soup is a Mexican-inspired stovetop soup with tender chicken, tomatoes, peppers, zucchini, and a warmly spiced broth. Serve it hot with lime, cilantro, avocado, or cheese; leaving out beans, corn, and rice keeps the bowl focused on chicken and vegetables while still making it hearty.

Soups made with chicken, chiles, tomatoes, and local vegetables vary across Mexican regions and family kitchens, so this is one flexible version rather than a claim to a single traditional formula. The broth has a gentle, adjustable heat, and the toppings let everyone finish a bowl to taste.

Ingredients

1½ lb boneless, skinless chicken thighs (680 g), trimmed
1 tbsp avocado oil or olive oil (15 ml)
1 medium yellow onion, diced, about 1 cup (150 g)
1 red bell pepper, diced, about 1 cup (150 g)
2 celery ribs, diced, about 1 cup (100 g)
3 garlic cloves, finely chopped, about 1 tbsp (9 g)
1 medium jalapeño, seeded for milder soup or left seeded for more heat, minced (about 15 g)
2 tbsp tomato paste (30 g)
1½ tsp ground cumin (about 3 g)
1 tsp chili powder (about 2.5 g)
½ tsp smoked paprika (about 1 g)
½ tsp fine salt (about 3 g), plus more to taste
¼ tsp ground black pepper (about 0.5 g)
1 can fire-roasted diced tomatoes, including juices, 14.5 oz (411 g)
6 cups low-sodium chicken broth (1.42 L)
1 medium zucchini, diced into small pieces, about 1½ cups (200 g)
2 tbsp fresh lime juice (30 ml), plus lime wedges for serving
½ cup chopped fresh cilantro (15 g), plus a little extra for serving
Optional toppings: 1 medium avocado, diced (about 150 g); ½ cup shredded Monterey Jack or cheddar (about 55 g); ½ cup sour cream (120 g); and ½ cup thinly sliced radishes (about 60 g)

Instructions

Prepare the ingredients. Dice the onion, bell pepper, celery, and zucchini; mince the garlic and jalapeño. If you prefer a mild broth, remove the jalapeño seeds and pale inner ribs before mincing. Pat the chicken dry with paper towels so it is easier to handle, and measure out the spices, tomatoes, and broth.
Soften the vegetables. Warm the oil in a large heavy pot or Dutch oven over medium heat. Add the onion, bell pepper, and celery. Cook for about 7 minutes, stirring occasionally, until the onion is translucent and the vegetables begin to soften. They do not need to brown; moderate heat helps them sweeten without scorching.
Bloom the seasonings and build the broth. Stir in the garlic, jalapeño, tomato paste, cumin, chili powder, smoked paprika, salt, and black pepper. Cook for 1 minute, stirring so the tomato paste darkens slightly and the garlic becomes fragrant. Pour in the diced tomatoes and broth, then stir to loosen any browned bits from the bottom of the pot.
Simmer the chicken. Nestle the chicken thighs into the broth and bring it just to a gentle boil. Lower the heat, cover the pot partially, and simmer gently for about 18 minutes. Avoid a hard boil, which can make the chicken tougher and cause the broth to reduce too quickly. Check the thickest thigh with an instant-read food thermometer; USDA FSIS says poultry must reach a safe minimum internal temperature of 165°F (74°C). If it has not reached that temperature, continue simmering and check again after a few minutes.
Shred the chicken. Transfer the cooked chicken to a clean plate with tongs and let it cool just enough to handle. Shred it into bite-size pieces with two forks, which should take about 3 minutes. Keep the broth at a gentle simmer while you work. If the chicken is too hot to handle safely, wait briefly rather than holding it in your hands.
Finish the soup. Add the zucchini to the pot and simmer for 5 minutes, until it is tender but still holds its shape. Return the shredded chicken to the broth and stir in the lime juice and cilantro. Heat for 2 minutes, taste, and adjust the salt, pepper, or lime. Ladle into bowls and add toppings just before serving.

Tips

Control the heat in stages. Jalapeños vary considerably in spiciness. Seed the pepper and use just half for a gentler soup, or omit it and add a pinch of cayenne at the table for anyone who wants extra heat. Chili powder blends also differ, so taste the broth before adding more. If you accidentally make the pot too spicy, extra broth and a creamy topping can soften the sensation, though they will also dilute the seasoning.

Choose the chicken cut that suits your schedule. Boneless thighs are forgiving and shred easily, while boneless, skinless chicken breasts work too. A thick breast may need a few extra minutes to reach 165°F (74°C), so use the thermometer rather than relying only on the clock. Bone-in chicken can add flavor, but it takes longer to cook and requires careful removal of bones and cartilage before shredding.

Keep the vegetables from turning mushy. Dice the zucchini into pieces of roughly the same size and add it near the end, not when the chicken first goes into the pot. If you want to include a vegetable that takes longer to soften, such as carrots, add it with the onion and celery. Add quick-cooking greens, like spinach, during the final minute or two.

Use the right tomato substitute. Fire-roasted tomatoes give the broth a lightly smoky, rounded flavor. If you cannot find them, ordinary diced tomatoes work well; add a small pinch of smoked paprika if you want to retain that smoky note. Tomato paste deepens the broth, but do not skip the brief cooking step, since stirring it into the oil and vegetables helps keep its flavor from tasting raw.

Serving Suggestions

Serve the soup in warmed bowls with lime wedges, chopped cilantro, and diced avocado. A little shredded Monterey Jack or cheddar melts into the hot broth, while sour cream adds a cool, creamy contrast. Thinly sliced radishes bring a crisp, peppery bite. Set out toppings separately so each person can choose how rich, fresh, or spicy to make a serving.

For a more substantial meal without adding rice or tortillas to the pot, pair the soup with a simple green salad dressed with lime and olive oil, or serve it with a small side of roasted cauliflower. If carbohydrates are not a concern for everyone at the table, warm corn tortillas or tortilla strips can be offered on the side rather than stirred into the shared pot. The soup also makes a satisfying first course before grilled vegetables or another simple main dish.

Variations

Make it creamier: Stir a few spoonfuls of sour cream into each bowl, or add a splash of heavy cream to the whole pot after turning off the heat. Avoid boiling the soup after adding dairy, since high heat can make it separate. Coconut milk is another option, but it gives the broth a noticeable coconut flavor that changes the Mexican-inspired seasoning profile.

Use a different chile: A minced serrano makes the soup hotter and sharper than jalapeño. For a deeper, dried-chile flavor, add a small amount of ancho chile powder in place of some of the chili powder; ancho is typically milder and fruitier. If dried ancho powder is not available, regular chili powder is a practical substitute, though the broth will be less rounded and less distinctly chile-forward.

Add more vegetables or beans: Chopped mushrooms, cauliflower florets, or a handful of spinach fit easily into the recipe. For a soup that is no longer low-carb, add drained black beans or corn near the end; each makes the pot heartier and changes its carbohydrate content. For a lower-starch variation, use extra zucchini or cauliflower instead. Keep additions moderate so the broth still covers the ingredients.

Make it with leftover cooked chicken: Skip the raw-chicken simmering step and stir in about 3 cups (420 g) cooked, shredded chicken after the zucchini has softened. Simmer until the chicken is thoroughly hot, stirring often. This shortens the cooking time, but the vegetables still need time to soften and the soup should be heated evenly before serving.

Storage and Reheating

Cool leftovers promptly and refrigerate them within 2 hours of cooking, in shallow, covered containers. The soup keeps for 3 to 4 days in the refrigerator. For the best zucchini texture, store toppings separately and add fresh avocado, cilantro, cheese, or sour cream when serving rather than before chilling.

Reheat only the portion you plan to eat, either in a saucepan over medium-low heat or in a microwave-safe bowl. Stir occasionally so the chicken and broth heat evenly; bring leftovers to 165°F (74°C), checking with a food thermometer. If the soup has thickened in the refrigerator, add a splash of broth or water. Freeze cooled soup in airtight containers for up to 3 months for best quality; leave a little space at the top for expansion. Thaw overnight in the refrigerator before reheating. Zucchini softens more after freezing, but the soup remains suitable for a quick meal.

Frequently Asked Questions

Is this soup keto-friendly?
It is made without beans, corn, rice, or tortillas in the pot, and its main ingredients are chicken, broth, and non-starchy vegetables. Exact carbohydrate totals depend on the broth, tomatoes, portion size, and toppings, so check product labels and calculate a serving from the ingredients you use if you track carbohydrates closely. Avoid sweetened broth or packaged seasoning mixes with added sugar.

Can I make the soup in a slow cooker?
Yes. For the best flavor, soften the onion, pepper, and celery in a skillet first, then bloom the garlic and spices before transferring them to the slow cooker with the tomatoes, broth, and raw chicken. Cook until the chicken reaches 165°F (74°C), checking with a thermometer; timing varies by cooker, so follow the appliance guidance rather than assuming one exact time. Add zucchini near the end so it does not become overly soft, then shred the chicken and stir in lime and cilantro.

Can I use rotisserie chicken?
Yes. Remove the skin and bones, shred about 3 cups (420 g) of cooked chicken, and add it after the zucchini is nearly tender. Let it simmer until hot throughout. Because rotisserie chicken is often salted, start with less added salt and adjust the finished broth only after tasting it.

What can I use instead of zucchini?
Cauliflower florets are a useful low-starch substitute; simmer them until tender, usually several minutes longer than small zucchini pieces. Chopped green beans also work and keep a firmer texture. If you use spinach, kale, or another leafy green, add it near the end and cook only until wilted or tender.

Why is my soup bland, and how can I fix it?
Broth varies in salt and strength, and a pot can taste muted if it needs more salt or acidity. First taste a spoonful, then adjust salt a little at a time. Add lime juice gradually for brightness, or add a small pinch of chili powder for more warmth. If the broth is too concentrated or salty, dilute it with unsalted broth or water and taste again.

Can I prepare parts of the recipe ahead?
Yes. Dice the onion, pepper, celery, and zucchini and refrigerate them in covered containers for up to 2 days. You can also measure the dry spices in advance. Keep raw chicken sealed on the lowest refrigerator shelf, separate from ready-to-eat ingredients, and cook it within the package’s safe-use window. For the freshest flavor, add lime juice and cilantro after cooking rather than prepping them into the soup far ahead.

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Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes

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