SERVES 6 TO 8 This recipe is a great way to make use of leftover cooked or raw vegetables. And make it DF by subbing dairy-free milk for regular milk and skipping the cheese. Regardless, wrap whatever you don’t eat and store it in the fridge for future breakfasts or lunch (the frittata is awesome at room temp with a salad alongside).
8 eggs, lightly beaten
1/4 cup milk or cream
Kosher salt and freshly ground pepper
3 tablespoons extra-virgin olive oil
1/2 cup diced or sliced onion
2 cups diced or sliced assorted raw or cooked vegetables (such as sweet pepper, zucchini, summer squash, asparagus, mushrooms, and potato)
4 ounces baby spinach (optional)
1/2 cup grated or crumbled cheese (such as gruyère, feta, or chèvre)
1/4 cup chopped mixed fresh herbs of choice (such as parsley, tarragon, and basil; optional)
Preheat the oven to 350°F. In a medium bowl, combine the eggs and milk. Season with 3/4 teaspoon salt and 1/4 teaspoon pepper. Set aside.
In a 10-inch ovenproof nonstick skillet over medium-high heat, warm the olive oil. Add the onion, 1/8 teaspoon salt, and a grind or two of pepper. Cook, stirring a few times, for 3 minutes. Add the assorted vegetables and cook, stirring occasionally, until the vegetables are soft and beginning to color, about 5 minutes longer. Stir in the spinach and cook, stirring, until wilted, about 2 minutes.
Whisk the egg mixture, then pour it into the skillet with the vegetables. Stir to combine. Evenly distribute the cheese and herbs over the top, then cook until the edges start to pull away from the sides of the pan, 6 to 8 minutes.
Place skillet in the oven and bake until set, 15 to 20 minutes. Cut and serve from the pan or turn out onto a platter, cut, and serve.