Preheat oven to 350°F. Grease a 9x13 inch cast pan or oil and cast iron skillet. See notes below*.
First, sauté the bell pepper, onion, and breakfast sausage with olive oil on medium heat in a large saucepan.
After about 10 minutes, the sausage should be browned. Add the garlic powder, onion powder (if using), oregano, Italian seasoning, and cayenne pepper.
Once the spices are fully coating the add-ins, remove the pan for heat. Pour the sausage mixture into a greased pan.
Next, whisk together the eggs and milk in a mixing bowl. Add the salt and black pepper. Do not over-whisk, but make sure the egg yolks are broken and the mixture is homogenous.
Pour the egg mixture over the sausage mixture into the pan.
Bake your frittata for 45 minutes. Let cool slightly before serving! The frittata can be in the refrigerator for about 1 week. Microwave for 1 minute to reheat.