French Onion Soup In Crock-Pot

Prep: 15 min Cook: 480 min Serves: 6 Cuisine: French

French Onion Soup is a comforting classic that combines the rich flavors of caramelized onions with savory beef stock. Topped with melted cheese and crusty bread, it’s perfect for chilly evenings and pairs wonderfully with a glass of red wine. Ideal for gatherings or a cozy night in.

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Ingredients

  • 1 qt. beef bouillon or brown stock
  • 3 c. thinly sliced yellow onions
  • 3 Tbsp. butter
  • 1 tsp. salt
  • 1 Tbsp. sugar
  • 2 Tbsp. flour
  • 1 c. grated Parmesan cheese

Instructions

  1. Pour bouillon or stock in crock-pot.
  2. Cook onions slowly in a large skillet in butter.
  3. Cover and let cook about 15 minutes.
  4. Uncover and add salt, sugar, and flour.
  5. Stir well.
  6. Add to stock in crock-pot.
  7. Cover and cook on low for 6 to 8 hours (or high for 3 hours).
  8. Before serving, top with grated cheese.
  9. If you have oven-safe bowls, place finished soup in individual bowls.
  10. Place a slice of Italian bread and a slice of Mozzarella cheese on top and place the bowl under the broiler until cheese melts.

Tips & Substitutions

For a deeper flavor, consider adding a splash of white wine while cooking the onions. If you're short on time, use pre-sliced onions or frozen ones. For a vegetarian version, substitute vegetable broth for beef bouillon and use olive oil instead of butter. Adjust the cheese type for a unique twist, like Gruyère for a classic French touch.

Serving Suggestions

Serve the French Onion Soup hot, topped with the melted cheese and crusty Italian bread for a satisfying dish. It pairs beautifully with a light salad or a side of roasted vegetables. For an added touch, serve with a glass of white wine, which complements the flavors of the soup perfectly.

Storage & Reheating

Store any leftovers in an airtight container in the refrigerator for up to 3 days. To reheat, warm the soup on the stove over medium heat, stirring occasionally until hot. If you prefer, you can microwave it in a microwave-safe bowl, covered loosely, for about 2-3 minutes, stirring halfway through.

Nutrition & Diet Analysis (per serving)

Each serving of French Onion Soup In Crock-Pot contains roughly 260 calories, with 8g protein, 47g carbohydrates, and 6g fat. It is an excellent source of vitamin C (64% of the Daily Value) and dietary fiber (26% of the Daily Value), and a good source of protein and iron. Note that it is relatively high in sodium, at 1304mg per serving (57% of the Daily Value).

260 kcal 13% DV
Protein Fat Carbs

Macronutrients

Protein 8.1g 16% DV
Total Fat 6.2g 8% DV
Carbs 47.3g 17% DV
Fiber 7.2g 26% DV
Sugar 0.2g

Electrolytes

Sodium 1304.5mg 57% DV
Potassium 460.1mg 10% DV
Cholesterol 17mg 6% DV

Vitamins & Minerals

Vitamin A 4mcg
Vitamin C 57.3mg 64% DV
Calcium 120.1mg 9% DV
Iron 1.8mg 10% DV
Diet fit High-fiber Under 400 cal Low-fat
Contains Milk Wheat/Gluten

Estimated from ingredients & per-serving nutrition — verify against package labels for allergies or strict diets.

* % Daily Values based on a 2,000 calorie diet (FDA 2020).

Frequently Asked Questions

Can I use other types of cheese?

Yes, while Parmesan is a great choice, you can also use Gruyère or a blend of cheeses for a richer flavor. Just make sure the cheese melts well for that classic topping effect.

How can I make this soup vegetarian?

To make a vegetarian version, simply replace the beef bouillon with vegetable broth and use olive oil instead of butter. This will maintain the soup's depth of flavor while keeping it meat-free.

Can I prepare this soup ahead of time?

Absolutely! You can prepare the soup a day in advance and store it in the fridge. Just reheat it before serving and top with cheese and bread as directed. This allows the flavors to meld beautifully.

Nutrition is estimated from USDA FoodData Central ingredient data and may vary with brand, portion and preparation — see our methodology. This information is for general educational purposes only and is not medical or dietary advice (disclaimer).

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