Campbell’s French Onion Soup with Toasted Cheese Bread

Campbell’s French onion soup is the shortcut base for this cozy, gratinée-style bowl, enriched with sweet sautéed onion and finished with toasted baguette and melted Gruyère. The canned soup brings savory onion flavor quickly, while a little low-sodium broth and water loosen its concentrated texture without making the finished soup too salty.

Ingredients

2 tablespoons (28 g) unsalted butter
1 large yellow onion (about 250 g), thinly sliced
½ teaspoon (2 g) granulated sugar, optional, to help the onion brown
¼ teaspoon (0.5 g) freshly ground black pepper
2 cans (10.5 ounces / 298 g each) Campbell’s Condensed French Onion Soup
2½ cups (600 ml) low-sodium beef broth
2½ cups (600 ml) water
4 baguette slices, about ½ inch (1.25 cm) thick and 1½ ounces (about 42 g) each
1½ cups (150 g) shredded Gruyère cheese
1 tablespoon (4 g) chopped fresh parsley, optional, for serving

The condensed soup is seasoned already, so this recipe uses low-sodium broth and waits until the soup is hot before deciding whether it needs salt. Gruyère melts smoothly and gives the topping a nutty flavor; Swiss cheese is an easy substitute with a milder taste. Use oven-safe soup bowls if you plan to melt the cheese directly on top under the broiler.

Instructions

Get everything ready. Slice the onion, shred the cheese if it is not already shredded, and cut four baguette slices. Set four broiler-safe bowls on a sturdy baking sheet. Begin heating the broiler while the onion cooks so it is ready when needed.
Soften and brown the fresh onion. Melt the butter in a large saucepan or Dutch oven over medium heat. Add the sliced onion, sugar if using, and black pepper. Cook for about 18 minutes, stirring every few minutes and lowering the heat if the onion starts to scorch. It should be soft and golden with a few deeper brown edges, not dry or crisp. If the pan gets very dark in spots, stir in a tablespoon of water and scrape up the browned bits.
Make the soup. Stir in both cans of condensed French onion soup, the beef broth, and the water. Bring the mixture just to a gentle simmer, stirring so the condensed soup blends evenly into the liquid. Reduce the heat to low and simmer for 10 minutes. Avoid a hard boil, which can make the soup reduce too much and intensify its saltiness. Taste before adding any salt.
Toast the baguette. While the soup simmers, arrange the bread slices on a baking sheet. Once the soup has simmered, toast the bread under the broiler for about 2 minutes per side, watching closely. The slices should be lightly crisp and dry on the surface, but they do not need to be dark brown. Remove the sheet and leave the broiler on.
Top and broil. Ladle the hot soup into the four oven-safe bowls, leaving enough room at the top to add bread without overflowing. Float one toasted baguette slice in each bowl and divide the Gruyère evenly over the bread. Put the bowls on the baking sheet and broil for about 2 to 3 minutes, until the cheese is melted, bubbling, and spotted golden. Broilers vary, so stay nearby and remove the bowls as soon as the cheese is ready. Carefully transfer the hot bowls to heatproof plates and finish with parsley if desired.

If you do not have broiler-safe bowls, do not put ordinary ceramic or glass bowls under the broiler. Instead, broil the cheese-topped bread on a baking sheet until melted, then place one slice on each bowl of soup. The soup will still taste rich and the topping will remain crisp, though you will not get the classic browned cheese cap over the whole bowl.

Tips

Keep the salt in check. Condensed soup can be quite salty, and regular beef broth adds more. Choose low-sodium broth, use the measured water, and taste only after the soup has simmered before adding salt. If it tastes too strong, stir in a little more hot water or unsalted broth.
Give the onion time. Medium heat and occasional stirring help the fresh onion turn sweet and golden without burning. If the onion browns too quickly, lower the heat; if it releases liquid, keep cooking until that moisture evaporates. The canned soup supplies plenty of onion flavor, so the fresh onion does not need to become deeply caramelized.
Use bread that can hold its shape. A day-old baguette or firm country loaf works well. Toasting dries the surface so the bread does not immediately collapse into the soup. Very thin sandwich bread tends to become soft quickly, so toast it thoroughly or serve it alongside instead.
Protect hands and surfaces. Broiled soup bowls are extremely hot, including the handles and rims. Use dry oven mitts, set bowls on heatproof plates, and let them stand briefly before eating. Keep the bowls stable on the baking sheet when moving them.

Serving Suggestions

Serve the soup immediately while the cheese is bubbling and the bread still has some crispness. A green salad with a sharp vinaigrette is a good counterpoint to the rich broth and cheese; try mixed greens, sliced pear, or bitter leaves such as endive. Roasted green beans or a simple plate of steamed vegetables also work when you want a more substantial meal without adding another heavy course.

For a larger dinner, pair a smaller bowl with a roast chicken sandwich, a simple ham sandwich, or a cheese omelet. If serving the soup as the main course, plan on one generously topped bowl per person and offer extra baguette at the table. Put the parsley on just before serving so it stays bright. A little freshly ground pepper can be added at the table, but extra salt is rarely needed.

Variations

Make it vegetarian: Replace the beef broth with low-sodium vegetable broth. The finished soup will be lighter and less beefy, while the condensed French onion soup and browned onion still provide a savory base. Check the soup label if you need to avoid a particular ingredient, because product formulations can change.

Change the cheese: Use shredded Swiss for a mild, familiar topping, or combine Gruyère and Swiss for a balanced melt. Provolone is another practical choice, though it tastes less nutty. Avoid piling on a very thick layer; a modest covering melts more evenly and is less likely to spill over the bowls.

Add mushrooms: Cook 6 ounces (170 g) sliced cremini mushrooms in the butter until their moisture has evaporated and they begin to brown, then add the onion and continue with the recipe. This adds an earthy note and makes the soup more substantial. The extra mushrooms may release liquid, so allow a few additional minutes for browning rather than turning up the heat too high.

Skip the broiler bowls: Serve the soup in regular bowls with the cheese-topped toast on the side. For a crispier topping, broil the bread and cheese on a baking sheet and place it on the soup just before eating. This is the best option if your bowls are not marked safe for broiler use or if you want to prepare the servings at the table.

Storage and Reheating

For the best texture, store the soup separately from the bread and cheese. Let the soup cool, then refrigerate it in a covered container within 2 hours of cooking. It keeps for 3 to 4 days in the refrigerator. Keep toasted bread in a separate airtight container at room temperature for about a day; refrigerating it can make it stale or soft. Shredded cheese can be stored separately in the refrigerator according to its package directions.

Reheat only the amount of soup you plan to serve. Warm it in a saucepan over medium-low heat, stirring occasionally, until steaming throughout; add a splash of water or broth if it has thickened. You can also microwave it in a microwave-safe bowl, stirring halfway through so the center heats evenly. USDA FSIS guidance is to reheat leftovers to 165°F (74°C); check with a food thermometer. Toast fresh bread, add cheese, and broil just before serving rather than storing assembled bowls, since bread left in soup becomes soggy and melted cheese does not reheat as neatly.

The soup base can also be frozen without its bread or cheese. Cool it promptly, pack it in a freezer-safe container with room for expansion, and freeze for up to 2 months for best quality. Thaw overnight in the refrigerator and reheat as above. The onion may soften further after freezing, but stirring well as the soup warms helps bring the texture back together.

Frequently Asked Questions

Is Campbell’s French onion soup condensed?

This recipe is written for Campbell’s Condensed French Onion Soup, sold in small cans and intended to be diluted. Product names and package sizes may differ by store or region, so check the label before cooking. If you have a ready-to-serve version rather than condensed soup, do not add the full amount of water and broth here; warm it according to its label and adjust the dilution to taste.

Can I make the soup without fresh onion?

Yes. The canned soup already contains onion, so you can omit the fresh onion, butter, and sugar if you want a quicker version. Start by combining the condensed soup with the measured broth and water, then simmer for 10 minutes before finishing with toast and cheese. The result will have less sweetness and texture from browned fresh onion, but it remains a useful shortcut.

What can I use instead of Gruyère?

Swiss cheese is the closest easy-to-find substitute and melts well, with a gentler flavor. Provolone or a mild white melting cheese also works, though each changes the topping’s character. Shred the cheese yourself if possible, since some pre-shredded cheeses have coatings that can make them melt less smoothly.

Can I prepare this ahead?

You can cook the soup base up to 3 days ahead and refrigerate it promptly in a covered container. Reheat it, toast the bread, and add the cheese immediately before serving. The assembled soup is not a good make-ahead dish: the bread absorbs broth and loses its crispness, and the cheese topping is best freshly melted.

Why did my soup taste too salty?

The condensed soup is already seasoned, so regular broth, extra salt, or cooking the liquid down too far can push the flavor past balanced. Use low-sodium broth and the stated water, simmer gently, and taste before seasoning. If the finished soup is too salty, dilute it with a little hot water or unsalted broth rather than adding sugar, which can make the flavor oddly sweet.

Do I need oven-safe bowls?

Only if you want to broil the cheese directly over the soup. Check the bowl manufacturer’s guidance; a bowl that is oven-safe is not automatically safe under a broiler, where heat is intense and direct. When in doubt, broil the toast and cheese on a baking sheet, then serve it on top of soup in ordinary bowls.

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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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