Vegetable Frittata Recipe

0 Preheat the oven to 350 °F.
1 Press a piece of parchment paper down into a 9-inch cake pan, 9-inch springform pan, or 8-inch square baking pan, crumpling it to tuck it down in the corners. It doesn't need to be perfect but should completely line the pan. This will make the frittata easy to remove from the pan after cooking (frittatas get sticky!). Spray the parchment paper lightly with nonstick cooking spray. 
2 In a mixing bowl, whisk together the eggs, milk, ½ teaspoon salt, and 1/2 teaspoon black pepper until evenly combined. 
3 Heat a 10-inch nonstick pan over medium heat. Add the butter and let it melt.
4 To the skillet, add the vegetables and remaining ½ teaspoon of salt. Cook until the vegetables are tender and heated through, 4 to 6 minutes if using raw vegetables or just 1 minute if using pre-cooked. Add the greens and cook until the greens are wilted. 
5 Pour the eggs into the prepared pan. Add the cooked vegetables and cheese and stir gently, folding some of the vegetables and cheese into the center of the frittata and leaving some on top. 
6 Bake the frittata in the oven until the center is just set (it should still jiggle a little when you shake the pan), 30 to 35 minutes. 
7 Let the frittata rest for 5 minutes at room temperature. Slice and serve!