Savory French Onion Soup with Caramelized Onions and Gruyère

By , Test Kitchen Director · Reviewed by AislePrompt Editorial · ·

Traditional French onion soup featuring deeply caramelized onions simmered in beef broth, topped with toasted baguette and melted Gruyère cheese. This french-inspired soups (vegetarian option with broth swap) ready in about 90 minutes pairs yellow onions, unsalted butter, olive oil for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 350 calories and feeds 4, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

★ 4.0 (9 ratings) Prep: 15 min Cook: 75 min Serves 4 French cuisine 350 cal/serving
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Ingredients

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Instructions

  1. Step 1: In a large heavy-bottomed pot, melt 3 tbsp unsalted butter and 1 tbsp olive oil over medium heat. Add 4 large thinly sliced yellow onions and 1 tsp sugar. Cook slowly, stirring frequently, for 40 minutes until onions are deeply caramelized and golden brown.
  2. Step 2: Pour in 1/2 cup dry white wine and cook for 5 minutes, scraping up any browned bits from the pot bottom.
  3. Step 3: Add 6 cups beef broth, 3 fresh thyme sprigs, 1 bay leaf, 1 tsp salt, and 1/2 tsp black pepper. Bring to a simmer and cook gently for 30 minutes to meld flavors.
  4. Step 4: Meanwhile, preheat broiler. Arrange 8 slices of baguette on a baking sheet and toast under broiler for 2 minutes per side until golden and crisp.
  5. Step 5: Remove thyme sprigs and bay leaf from the soup. Ladle soup into oven-safe bowls, place toasted baguette slices on top, and sprinkle evenly with 2 cups shredded Gruyère cheese.
  6. Step 6: Place bowls under broiler for 3-4 minutes until cheese is melted, bubbly, and lightly browned. Serve immediately.

Frequently asked questions

How long does Savory French Onion Soup with Caramelized Onions and Gruyère take to make?

Total time is about 90 minutes (15 min prep + 75 min cook). Most home cooks find this fits comfortably into a weeknight; double the batch on Sunday for two dinners.

How do I store leftover Savory French Onion Soup with Caramelized Onions and Gruyère?

Cool to room temperature within 2 hours, then store in an airtight container in the fridge for up to 4 days. Reheat covered in a 350°F oven for 10-12 minutes, or microwave at 70% power in 60-second bursts to keep yellow onions from drying out.

Can I substitute ingredients in Savory French Onion Soup with Caramelized Onions and Gruyère?

Yes — most ingredients in this recipe have flexible swaps. For oil, use any neutral high-smoke-point oil (avocado, grapeseed, refined coconut). For aromatics, dried herbs at ⅓ the volume of fresh work in a pinch. The full ingredient list is shoppable on Instacart so you can see substitutes in real time.

How do I scale Savory French Onion Soup with Caramelized Onions and Gruyère for a different number of people?

The recipe is written for 4 servings. Multiply each ingredient by (your serving target / 4). Cook time stays roughly the same up to 2x; for 3-4x batches, switch from a skillet to a sheet pan or stockpot so the food isn't crowded — overcrowding steams instead of browns.

Is Savory French Onion Soup with Caramelized Onions and Gruyère vegetarian option with broth swap?

Yes — this recipe is tagged vegetarian option with broth swap based on its ingredient list. Always cross-check labels for packaged ingredients (sauces, broths, condiments) since formulations vary by brand.

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