Authentically Brewed French Onion Soup with Beef Stock

By AislePrompt Editorial · Published 2026-04-02 · Updated 2026-04-02

A classic French soup where onions are caramelized slowly over low heat for 45 minutes, then simmered with rich beef stock and a toasted baguette topping. This French-inspired soup recipe, ready in about 70 minutes, pairs yellow onions, beef stock, butter for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 280 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.

Ingredients

• 6 medium, thinly sliced yellow onions
• 3 cups beef stock
• 3 tbsp butter
• 1 tbsp all-purpose flour
• 1 slice, cut into 1/2-inch cubes baguette
• 1/2 cup, grated Gruyère cheese

The stock pot we’d simmer this in → Best Stock Pots for 2026: Top Picks + Buying Guide

Instructions

1. Step 1: Melt 3 tbsp butter in a heavy-bottomed pot over medium-low heat, add 6 medium thinly sliced yellow onions, and cook uncovered for 45 minutes, stirring occasionally until deeply caramelized and golden brown.
2. Step 2: Sprinkle 1 tbsp all-purpose flour over onions and stir constantly for 2 minutes to form a paste, then slowly whisk in 3 cups beef stock until smooth.
3. Step 3: Bring to a gentle simmer and cook uncovered for 20 minutes, allowing flavors to meld and the soup to thicken slightly.
4. Step 4: Preheat oven broiler, then arrange 1 slice baguette cubes in a baking dish, top with 1/2 cup grated Gruyère cheese, and broil for 3-4 minutes until cheese is bubbly and golden.
5. Step 5: Ladle hot soup into bowls, top with a cheese-topped baguette cube, and serve immediately.