Oven Baked Onion Soup
Oven baked onion soup features sweet, caramelized onions in a rich beef broth, topped with toasted French bread and melted Swiss cheese, then finished with Parmesan. This comforting dish offers deep savory flavors, perfect for cozy gatherings or a hearty starter for any meal.
Ingredients
Instructions
- Melt butter in a large heavy Dutch oven or soup pot.
- Saute onions over medium-low heat, stirring occasionally until light brown.
- Sprinkle flour over the onions; stir into onions.
- Stir in beef broth, white wine, salt, and pepper.
- Heat to boiling.
- Reduce heat; simmer, uncovered, for 10 minutes.
- Place a slice of toasted French bread in each of 6 small ovenproof soup dishes.
- Ladle the soup over the bread.
- Place one slice of Swiss cheese on each soup dish; sprinkle with Parmesan cheese.
- Bake at 375°F until cheese melts, about 5 minutes.
- Serve hot.
Tips & Substitutions
For a deeper flavor, caramelize the onions longer until they are a rich golden brown. You can substitute vegetable broth for a vegetarian option, and Gruyère cheese can be used instead of Swiss for a nuttier taste. If you prefer a thicker soup, add more flour or reduce the broth slightly. This recipe is reminiscent of traditional American recipes, making it a comforting choice.
Serving Suggestions
Serve the soup hot, garnished with additional Parmesan cheese if desired. It pairs beautifully with a crisp green salad or a side of roasted vegetables. For a heartier meal, consider serving it alongside a steak sandwich. A glass of dry white wine can enhance the flavors of the dish beautifully.
Storage & Reheating
Store any leftover soup in an airtight container in the refrigerator for up to 3 days. To reheat, gently warm it on the stove over medium heat, adding a splash of beef broth if it thickens too much. Avoid reheating in the microwave as it can alter the texture of the cheese.
Nutrition & Diet Analysis (per serving)
Each serving of Oven Baked Onion Soup contains roughly 1289 calories, with 68g protein, 27g carbohydrates, and 101g fat. It is an excellent source of calcium (154% of the Daily Value), protein (135% of the Daily Value), and vitamin A (80% of the Daily Value). Note that it is relatively high in sodium, at 1751mg per serving (76% of the Daily Value).
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 make this soup in advance?
Yes, this soup can be made in advance and stored in the refrigerator for up to 3 days. When ready to serve, simply reheat on the stovetop and proceed with the bread and cheese topping before baking.
Is it possible to make this soup vegetarian?
Absolutely! To make a vegetarian version, substitute the beef broth with vegetable broth and skip the cheese or use a plant-based cheese alternative. The flavor will still be rich and delicious.
How can I make the soup thicker?
To thicken the soup, you can add more all-purpose flour while sautéing the onions or reduce the amount of broth added. A cornstarch slurry can also be used as a thickening agent if you want a quicker method.
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).