Preheat oven to 375°F and lightly grease a 9-inch pie dish.
In a large bowl, whisk together the eggs, milk, garlic powder, onion powder, salt, and pepper.
Stir in the shredded cheese and chopped vegetables.
Pour the mixture into the prepared dish, spreading out the veggies evenly.
Bake for 35 to 40 minutes, or until the quiche is set in the middle and lightly golden on top.
Let it cool for 5 to 10 minutes before slicing and serving.