Preheat your oven to 350°F (175°C).
Grease a 9-inch pie dish or quiche pan.
In a large bowl, whisk together the eggs and milk until well combined.
Add salt, pepper, and garlic powder to the egg mixture.
Stir in the shredded cheese and chopped vegetables.
Pour the mixture into the prepared pie dish.
Bake in the preheated oven for 30-35 minutes, or until the center is set.
Check for doneness by inserting a toothpick; it should come out clean.
Allow the quiche to cool for a few minutes before slicing.
Serve warm or at room temperature.