In college, I had all the Molly Katzen vegetarian cookbooks- Moosewood, The Enchanted Broccoli Forest-and one of them had a genius formulation to simplify a limitless combination of quiches by just choosing a cheese and a cooked vegetable: the crust and egg custard are always the same.
All quiches have four layers: crust + cheese + filling + custard.
For the shell, you can buy or make any regular pie crust you prefer. You can even skip the shell entirely, or use cooked potatoes and call it a frittata. But I digress…
For the custard, beat 4 eggs with one cup whole milk and a pinch of salt. (Or 6 eggs +1.5 cups milk for deep dish.) You can also substitute fresh milk for a can of evaporated milk for a denser custard.
Now comes the fun part- choose your cheese and filling combination.
Here are some of my favorites, I often combine multiple fillings too. You can roast or sauté any vegetable, chop cured meats, or even use leftovers (diced pork tenderloin anyone?)
Swiss, Gruyere or Comte + Bacon (the classic Lorraine)
Goat Cheese or Feta + Chopped Heirloom Tomatoes + Fresh Basil
Cheddar or Swiss + Sautéed Spinach and shallots
Goat Cheese, Gruyère, or Parmesan + Roasted Asparagus, chopped
Swiss + Mushrooms sautéed in butter with thyme
Crumbled Blue Cheese + Carmelized Onions
Jack Cheese + Roasted Broccoli
Add the cheese to the pie shell and bake briefly to melt the cheese and create a barrier between the liquid and crust. Then remove from the oven, add the filling, pour the custard on top and bake about 45 minutes until the custard is set.