True-Blue French Onion Soup

By · Reviewed by AislePrompt Editorial · ·

A deeply caramelized onion soup made with slowly cooked onions and a rich beef stock, embodying the authentic French technique without modern substitutions. This french-inspired soups ready in about 85 minutes pairs Yellow onions, Butter, Beef stock for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 320 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.

Prep: 30 min Cook: 55 min Serves 6 French cuisine 320 cal/serving
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Ingredients

Instructions

  1. Step 1: Thinly slice 1 lb yellow onions and cook in 3 tbsp butter over medium-low heat for 45-50 minutes, stirring occasionally until deeply caramelized and golden brown, not browned.

Equipment for this recipe

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Frequently asked questions

How long does True-Blue French Onion Soup take to make?

Total time is about 85 minutes (30 min prep + 55 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 True-Blue 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 yellow onions from drying out.

Can I substitute ingredients in True-Blue 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 True-Blue French Onion Soup 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 True-Blue 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.

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