French Onion Frittata – A Classic Twist on Easy Recipes for Dinner
This French Onion Frittata is the ultimate comfort food that combines the richness of caramelized onions with fluffy eggs and gooey cheese. Perfect for easy recipes for dinner, this dish also fits into your rotation of quick and easy recipes, vegetarian easy recipes, sweet easy recipes, easy meal recipes, air fryer easy recipes, and breakfast easy recipes.
Servings: 6 servings
Ingredients
- 2 tablespoons unsalted butter
- 2 large yellow onions, thinly sliced
- 1/2 teaspoon kosher salt, plus more as needed
- 1/4 teaspoon freshly ground black pepper
- 1/4 cup low-sodium chicken or vegetable broth
- 8 large eggs
- 1/4 cup whole milk
- 1 tablespoon Dijon mustard
- 1 cup shredded Gruyère cheese, divided
- Chopped fresh thyme leaves, for garnish (optional)
Instructions
- Preheat oven to 400°F (200°C).
- Melt butter in a large oven-safe skillet over medium heat. Add onions, salt, and pepper. Cook, stirring occasionally, until caramelized, about 25 minutes.
- Add broth and cook until mostly evaporated, about 2 minutes.
- In a large bowl, whisk together eggs, milk, mustard, and 1/2 cup of the cheese.
- Pour egg mixture into the skillet over the onions. Stir gently to combine.
- Sprinkle the remaining cheese on top and transfer the skillet to the oven.
- Bake until the frittata is puffed and golden, 15–18 minutes.
- Let cool slightly, garnish with thyme if using, slice, and serve.