Baked Frittata

8 large eggs
½ cup whole milk
Kosher salt and black pepper
½ cup finely diced bacon
1 cup diced onion (from 1 small onion)
2 cups diced red or orange bell peppers (from 2 peppers)
1 (5-ounce) package baby spinach
4 ounces fresh goat cheese

1. Heat oven to 375 degrees. In a medium bowl, beat eggs, milk, 1 teaspoon salt and ½ teaspoon pepper until smooth. Set aside.
2. Put bacon in a 10- to 12-inch cast-iron or oven-safe nonstick skillet. Set over medium heat and cook, stirring occasionally, until browned, 4 to 5 minutes.
3. Add onion, peppers and ½ teaspoon each salt and pepper and cook, stirring often, until onions are translucent, 6 to 7 minutes. Add the spinach a handful at a time, stirring after each addition, to wilt.
4. Reduce heat to low and pour in the egg mixture. Stir well to evenly distribute the vegetables, then smooth the top. Drop small nuggets of goat cheese evenly on top. Transfer to the oven.
5. Bake until the top is golden brown and the eggs are set, 20 to 25 minutes. When you shake the pan, the eggs shouldn’t jiggle. Cool on a rack for about 10 minutes.
6. Cut into wedges to serve warm or at room temperature.