Tuna and Lentils: A Bright, Hearty Salad

This tuna and lentil salad combines tender green or brown lentils, flaky canned tuna, crisp vegetables, herbs, and a lemon-Dijon dressing. Serve it slightly warm or chilled as a satisfying lunch or a simple supper; the flavors are flexible, with no single regional version claimed here.

Ingredients

1 cup (190 g) dry green or brown lentils, picked over and rinsed
3 cups (710 ml) water, plus more if needed for cooking
1 bay leaf
1 teaspoon (6 g) fine salt, divided, plus more to taste
2 cans tuna, 5 ounces (142 g) each, drained; use tuna packed in water or oil
1 cup (150 g) cherry tomatoes, quartered
2 medium celery stalks (about 100 g), thinly sliced
¼ small red onion (about 40 g), finely chopped
½ cup (15 g) chopped fresh flat-leaf parsley
2 tablespoons (30 ml) fresh lemon juice, from about 1 lemon
1 tablespoon (15 ml) red wine vinegar
1 teaspoon (5 g) Dijon mustard
3 tablespoons (45 ml) extra-virgin olive oil
¼ teaspoon (1 g) freshly ground black pepper
¼ teaspoon (½ g) dried oregano
¼ cup (30 g) pitted Kalamata olives, halved (optional)

Instructions

Rinse and sort the lentils. Spread them on a plate or tray and remove any small stones or shriveled lentils. Rinse under cool running water in a fine-mesh strainer. Green or brown lentils are a good choice because they usually hold their shape when simmered; red lentils soften and break down too much for this salad.
Simmer until just tender. Put the lentils in a medium saucepan with the water, bay leaf, and ½ teaspoon (3 g) of the salt. Bring to a boil over medium-high heat, then lower the heat so the water simmers gently. Cook uncovered for about 20 to 25 minutes. Start checking at 18 minutes: the lentils should be tender through the center but still intact, not mushy. Add a splash of hot water if the pan gets dry before they are done.
Drain and cool briefly. Remove the bay leaf, then drain the lentils well. Let them sit in the strainer for 2 to 3 minutes so excess water can drip away. Transfer them to a wide bowl and let them cool for about 5 minutes. They should still be warm, not steaming heavily; warm lentils take on the dressing well, while a little cooling helps keep the tuna from turning pasty when everything is mixed.
Make the dressing. In a small bowl, whisk together the lemon juice, red wine vinegar, Dijon mustard, olive oil, remaining ½ teaspoon (3 g) salt, black pepper, and oregano. Taste a drop and adjust the lemon or salt if needed. The dressing should taste lively on its own because the lentils will soften its sharpness.
Dress the lentils and vegetables. Add the tomatoes, celery, red onion, parsley, and optional olives to the warm lentils. Pour over about three-quarters of the dressing and fold gently with a broad spoon. Leave it for 5 minutes, then taste a lentil. Add the rest of the dressing if the mixture seems dry, or keep a little aside for serving.
Add the tuna without crushing it. Flake the drained tuna into large pieces with a fork and place it over the salad. Fold only two or three times, just enough to distribute it while keeping some recognizable flakes. Taste again and add salt, pepper, or a squeeze of lemon as needed. If you prefer a more composed look, leave the tuna in larger pieces and arrange it on top instead of folding it in.
Serve. Spoon the salad onto plates while it is slightly warm, or cover and chill it for a cooler meal. If it has been refrigerated, let it sit at room temperature for about 10 minutes before serving so the olive oil loosens and the flavors are easier to taste. Do not leave it out for more than 2 hours.

Tips

Choose lentils that stay firm. Green, brown, or French-style green lentils work well. Cooking time varies with age and variety, so check for tenderness early rather than relying only on the clock. Stop as soon as they are tender; a few extra minutes can make them split and turn the salad soft.
Drain both components thoroughly. Watery lentils dilute the dressing, and liquid left in the tuna can make the salad soggy. Drain the lentils well after cooking, and press the tuna lightly in its can lid or a strainer without squeezing it into a paste.
Adjust the onion to your taste. Red onion adds a crisp, sharp bite. For a milder flavor, soak the chopped onion in cold water for 5 minutes, then drain and pat it dry before adding it. You can also use sliced scallions, which taste gentler and fresher.
Use the tuna you have. Tuna packed in oil gives a richer salad; tuna packed in water keeps it lighter and lets the dressing stand out. If using oil-packed tuna, drain it well and consider reducing the olive oil in the dressing to 2 tablespoons (30 ml), then add more only if needed.

Serving Suggestions

This salad is substantial enough to serve on its own for lunch, but it also works as part of a larger meal. Spoon it over a bed of crisp lettuce or tender greens, with toasted bread or warm pita alongside to catch any dressing. For a more filling dinner, serve it with roasted carrots, grilled zucchini, or a simple vegetable soup. A bowl of sliced cucumbers or radishes adds extra crunch without competing with the lemon and herbs.

For a packed lunch, portion the salad into a sealed container and keep it chilled until serving. Pack crackers or bread separately so they do not soften. If you are serving guests, arrange the lentil mixture on a platter and add the tuna in large flakes on top, then finish with parsley, a few olives, and a small drizzle of olive oil. Put lemon wedges on the side for anyone who likes a sharper finish.

Variations

Mediterranean-style additions: Add ½ cup (75 g) diced cucumber or roasted red pepper, and use chopped fresh dill in place of some of the parsley. A little crumbled feta can be added at the table; it brings saltiness, so taste before adding extra salt. These are flexible flavor choices rather than requirements for a single traditional version.

Make it more substantial: Stir in 1 cup (150 g) cooked green beans, diced cooked potato, or cooked farro. If you add a grain, reserve some dressing and add it after mixing because the extra ingredient will absorb moisture. For a sharper salad, add 1 teaspoon (5 ml) capers, rinsed and chopped, and reduce the salt slightly.

Change the dressing: Use sherry vinegar or white wine vinegar instead of red wine vinegar in the same quantity. If you do not have Dijon mustard, use ½ teaspoon (2.5 g) whole-grain mustard; the dressing will have a milder mustard flavor and a slightly textured appearance. For a dairy-free creamy variation, mash ¼ ripe avocado (about 35 g) into the dressing and add a teaspoon or two of water to thin it. The salad will be less tangy and is best eaten soon after mixing.

Use another canned fish: Well-drained canned salmon or sardines can replace the tuna in equal drained weight. Salmon gives a softer, richer result, while sardines have a more assertive flavor, so begin with a smaller amount if you are unsure and adjust the lemon and parsley to suit.

Storage and Reheating

Refrigerate the salad in a covered, food-safe container within 2 hours of preparing it. Keep it at 40°F (4°C) or colder and use it within 3 to 4 days. For the freshest texture, store the lentils and dressing separately from the tuna and chopped vegetables, then combine portions just before serving. If already mixed, the salad is still suitable for storing, though the tomatoes will soften and the lentils will continue to absorb dressing.

This recipe is usually served cold or at room temperature, so reheating is optional. To serve it warm, heat only the portion you plan to eat in a covered microwave-safe dish or in a small pan over low heat, stirring gently until it reaches 165°F (74°C), the USDA FSIS safe minimum temperature for reheated leftovers. Avoid repeatedly warming and cooling the whole batch. Discard any portion left at room temperature for more than 2 hours, or more than 1 hour when the temperature is above 90°F (32°C).

Frequently Asked Questions

Can I use canned lentils instead of dry lentils?
Yes. Use about 2 cups (400 g) drained and rinsed canned lentils in place of the dry lentils, water, and bay leaf. Skip the simmering step and begin with the dressing. Canned lentils are convenient but can be softer and saltier, so drain them carefully and season the finished salad gradually.

Do I need to cook the canned tuna?
No. Commercially canned tuna is already cooked and can be drained and added directly to the salad. Keep the can refrigerated if it has already been opened, and use tuna from an undamaged can that is within its date. The temperature guidance for reheated leftovers applies only if you choose to serve a portion warm.

Why did my lentils turn mushy?
They may have simmered too long, or the lentils may have been a variety that breaks down easily. Check them before the suggested cooking time ends and drain them as soon as they are tender but still hold their shape. Red lentils are better suited to soups and dals than to a salad with distinct lentils.

Can I make this salad ahead?
Yes. Cook the lentils and prepare the dressing up to 2 days ahead, then refrigerate them separately in covered containers. Chop the onion and celery ahead if convenient, but add the tuna, tomatoes, and parsley on the day you plan to serve it for the best texture. Combine everything shortly before eating and adjust the dressing because chilled lentils may absorb some of it.

What can I use instead of tuna?
For another fish option, use drained canned salmon or sardines. For a meat-free version, leave out the tuna and add 1 cup (150 g) cooked chickpeas or white beans; the flavor will be milder, so extra lemon, olives, or capers can help give the salad more contrast. Store the altered salad chilled in the same way.

Is this salad better warm or cold?
Either works. Slightly warm lentils absorb the dressing readily and make the salad feel more like a supper, while chilling gives the flavors time to mingle and makes it convenient for packed lunches. If serving it cold, taste it again just before serving and add a little lemon juice or olive oil if the dressing has thickened or been absorbed.

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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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