Lightly dust a pie plate with flour. Mold a prepared pie crust (Pillsbury or store brand) into the pie plate. Set aside.
Sprinkle the prepared crust with shredded cheddar cheese, crumbled feta, and shredded Swiss. (Optional how much cheese you want to use and the flavor of cheese) I use a generous amount of cheese.
Saute thinly sliced veggies of your choice in a pan with 1 tbl. olive oil. (I add chopped fresh spinach to the pan for the last minute of sautéing.) Optional: add diced ham to this mixture. Pour veggies over the cheese.
In a bowl, whisk 5 eggs with 1 and 3/4 cups of half and half. Add 1 tsp. of 5-Onion Seasoning. For additional flavor, add 1/2 tsp. of Bacon and Onion seasoning. Pour over the veggies and cheese.
Bake in a preheated oven at 400 degrees for 15 minutes; then turn the temperature down to 300 degrees and bake another 30-35 minutes until the eggs have set and the egg topping is fluffy and firm.