Leanne Brown created this recipe for her cookbook Good and Cheap. She notes that you can use any vegetable that you like, and suggests steaming hard vegetables like broccoli, cauliflower or winter squash before adding them to the quiche. Tomatoes, zucchini, spinach and other quick cooking vegetables can be added fresh.
- Preheat the oven to 400 degrees.
- Melt the butter in a cast-iron or ovenproof skillet over medium heat. (If your skillet isn’t ovenproof, transfer everything to a pie plate in step 3 to bake it.) Add the onion slices and sprinkle a bit of salt and pepper over them. Cook the onions until they are golden brown and starting to caramelize, about 10 minutes.
- Remove the pan from the heat and spread the onions evenly across the bottom. Spread the vegetables evenly over the onions. The dish or pan should look fairly full.
- In a bowl, use a fork to beat the eggs lightly with the milk, cheese, 1 tsp of salt, and ½ tsp of pepper, just enough to break up the yolks and whites. This is a savory custard mixture. Pour the custard over the vegetables and onions and enjoy watching it fill in all the open spaces.
- Transfer the quiche to the oven and bake for 1 hour. Once the surface is lightly brown all the way across, it’s fully cooked.
- Let the quiche cool for about 20 minutes, then slice into wedges.