Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).

Mix all crust ingredients with a fork in a small bowl. If necessary, add a drop more oil to form a dough.

Press dough into a nine-inch (23-centimeter) deep dish pie pan, covering the bottom and sides. Bake for 10 minutes.

In a large frying pan sprayed with cooking spray, heat butter over medium heat until melted. Add onion and sauté for two minutes.

Add peppers and sauté for two minutes more. Continue adding each vegetable separately and sautéing two minutes more before adding the next one. (This ensures the most palatable texture for each vegetable.)

After all the veggies are added, sauté an additional 10 minutes, stirring occasionally. Turn up heat for the last two minutes. Remove from heat.

Stir in two-thirds cup Muenster cheese and mix well.

Turn the filling into the prebaked quiche crust, smoothing out the top.

In a small bowl, whisk together the milk, cooking cream, egg, and seasoning. Carefully pour over the veggies.

Bake for 30 minutes. If your milchig oven has this option, turn the oven setting to heat just from the bottom and bake an additional 10 minutes (this helps prevent crust from getting soggy). If not, cover the pie and bake for 10 minutes.

Sprinkle with remaining one-third cup Muenster cheese and bake on regular setting for an additional five minutes. Let sit about half an hour before serving.