Slow-Simmered French Onion Soup with Gruyère Crust
A deeply caramelized onion soup crowned with a golden, bubbling layer of Gruyère cheese, evoking old-world French kitchens with its simple, rich flavors. This french-inspired soups ready in about 105 minutes pairs yellow onions, unsalted butter, all-purpose flour for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 380 calories and feeds 6, 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
- 1.5 lbs, thinly sliced yellow onions
- 4 tbsp unsalted butter
- 1 tbsp all-purpose flour
- 1/2 cup dry white wine
- 4 cups beef stock
- 1/2 cup, grated Gruyère cheese
- 6 slices, toasted baguette slices
Equipment for this recipe
Top-rated tools to make this recipe successfully.
Instructions
- Step 1: Melt 4 tbsp unsalted butter in a heavy pot over medium-low heat. Add 1.5 lbs thinly sliced yellow onions and 1 tsp salt, stirring occasionally. Cook for 45-50 minutes until deeply golden and caramelized, scraping the pot bottom every 10 minutes to prevent sticking.
- Step 2: Sprinkle 1 tbsp all-purpose flour over onions and stir for 1 minute to cook off raw flour taste. Deglaze with 1/2 cup dry white wine, scraping up browned bits, and simmer until liquid reduces by half.
- Step 3: Pour in 4 cups beef stock, bring to a gentle simmer, and cook uncovered for 20 minutes. Ladle soup into oven-safe bowls, top each with 2 slices toasted baguette, then sprinkle 1/4 cup grated Gruyère over the bread. Broil 3-4 inches from heat for 2-3 minutes until cheese is bubbly and golden.
Frequently asked questions
How long does Slow-Simmered French Onion Soup with Gruyère Crust take to make?
Total time is about 105 minutes (25 min prep + 80 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 Slow-Simmered French Onion Soup with Gruyère Crust?
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 Slow-Simmered French Onion Soup with Gruyère Crust?
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 Slow-Simmered French Onion Soup with Gruyère Crust for a different number of people?
The recipe is written for 6 servings. Multiply each ingredient by (your serving target / 6). 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.
What goes well with Slow-Simmered French Onion Soup with Gruyère Crust?
French soups like this pair well with a simple grain (rice, couscous, or crusty bread), a quick salad with acid (lemon vinaigrette, pickled onions), and a pan sauce or yogurt-based dip. Tap "Plan a meal with the AI" to get specific side suggestions.
What others are saying
- ★★★★★
A classic done right. The soup was so comforting on a cold evening.
- ★★★★★
The slow-simmered method made the onions incredibly sweet. Gruyère crust was a genius idea.
- ★★★★★
The onions caramelized perfectly, and the Gruyère crust was divine. Made for my family and they loved it!
