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Step-by-Step Recipe
Ready to make restaurant-quality French onion soup in under 30 minutes? This foolproof recipe uses store-bought mix for convenience without sacrificing flavor. Follow these simple steps for perfect results every time:
- Prepare the base: Heat 2 tablespoons of butter in a large pot over medium heat. Add 4 cups of thinly sliced yellow onions and cook for 15-20 minutes until deeply caramelized, stirring occasionally.
- Add broth and mix: Pour in 4 cups of high-quality beef broth (homemade preferred) and stir in 1 packet of French onion soup mix. Bring to a gentle simmer for 5 minutes.
- Season and enhance: Add 1 tablespoon of dry sherry or red wine for depth, plus a pinch of fresh thyme. Simmer for another 3 minutes.
- Prepare toppings: Toast baguette slices until golden. Grate 1 cup of Gruyère cheese for melting.
- Assemble and serve: Ladle soup into oven-safe bowls. Place toasted bread on top, then sprinkle generously with cheese. Broil for 2-3 minutes until cheese is bubbly and golden.

Proper Storage for Maximum Freshness
Store your French onion soup mix correctly to maintain flavor and prevent clumping:
- Airtight container: Transfer mix to a glass or BPA-free plastic container with tight seal. Avoid original packaging which often isn't fully airtight.
- Cool, dark location: Store in pantry away from heat sources like stove or dishwasher. Ideal temperature is below 70°F (21°C).
- Freezing option: For long-term storage (over 6 months), freeze in small portions using freezer-safe bags. Thaw at room temperature before use.
- Check freshness: Discard if mix develops odd smell, clumps, or changes color to dark brown.

Choosing the Right Mix
Key Feature | Why It Matters | What to Look For |
---|---|---|
Real Onion Content | Ensures authentic flavor | Look for "dehydrated onions" as first ingredient, not just "onion powder" |
Minimal Additives | Healthier and better taste | Avoid mixes with MSG, artificial flavors, or excessive sodium |
Broth Base | Reduces need for extra broth | Check for powdered beef or vegetable broth in ingredients |
Brand Reputation | Consistent quality | Choose established brands like McCormick or Knorr with positive reviews |

Frequently Asked Questions
Can I make French onion soup without broth?
No, broth is essential for flavor and texture. Use beef broth for traditional flavor or vegetable broth for vegetarian version. Water alone will result in bland soup.
How do I fix soup that's too salty?
Add extra broth or water to dilute. For immediate solution, place a peeled raw potato in the soup for 10 minutes to absorb excess salt, then remove before serving.
Can I use frozen onions for this recipe?
Yes, but thaw completely first. Fresh onions caramelize better, but frozen work in a pinch. Avoid canned onions as they're too soft and watery.
What's the best cheese for topping?
Gruyère is traditional for its nutty flavor and excellent melt. Combine with Parmesan for extra sharpness. Avoid pre-shredded cheese which contains anti-caking agents that prevent proper melting.
How long does homemade French onion soup last?
Store in airtight container for 3-4 days in refrigerator. Freeze without bread and cheese topping for up to 3 months. Reheat gently on stove.
Conclusion
With just a store-bought mix and these simple techniques, you can create authentic French onion soup that rivals restaurant quality. The key is proper caramelization of onions, using quality broth, and finishing with melted cheese on toasted bread. By storing your mix correctly and choosing the right product, you'll consistently make delicious soup that warms both body and soul. Happy cooking!