Slow-Simmered French Onion Soup
A classic French comfort food featuring deeply caramelized onions simmered in rich broth, topped with a golden crust of melted Gruyère cheese. This french-inspired soups ready in about 90 minutes pairs grams yellow onion, tablespoons unsalted butter, tablespoon all-purpose flour 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.
Ingredients
- 700 grams yellow onion
- 2 tablespoons unsalted butter
- 1 tablespoon all-purpose flour
- 4 cups beef broth
- 120 milliliters dry white wine
- 50 grams Gruyère cheese
- 4 slices baguette
Instructions
- Step 1: Thinly slice 700 grams yellow onions and cook in 2 tablespoons unsalted butter over medium-low heat for 45-50 minutes until deeply golden brown, stirring occasionally to prevent burning.
- Step 2: Sprinkle 1 tablespoon all-purpose flour over onions, stir to coat, and cook for 1 minute.
- Step 3: Pour in 120 milliliters dry white wine, simmer for 5 minutes to evaporate alcohol, then add 4 cups beef broth and simmer uncovered for 20 minutes.
- Step 4: Ladle soup into oven-safe bowls, top each with 50 grams grated Gruyère cheese, and broil under high heat for 2-3 minutes until golden.
Frequently asked questions
How long does Slow-Simmered French Onion Soup take to make?
Total time is about 90 minutes (20 min prep + 70 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?
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 grams yellow onion from drying out.
Can I substitute ingredients in Slow-Simmered French Onion Soup?
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 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.
What goes well with Slow-Simmered French Onion Soup?
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
- ★★★★★
Loved it! So comforting on a cold evening. The recipe was easy to follow and the results were amazing.
- ★★★★★
Made this for my family and they loved it. The slow simmer really brought out the flavors. A new favorite!
- ★★★★★
This soup was divine! The onions were perfectly caramelized and the broth was rich. Served with a baguette, it was a perfect dinner.
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