Preheat oven to 375°F (190°C).
In a skillet over medium heat, add a drizzle of oil and sauté onion and garlic.
Once transparent, add sausage and cook until browned, 7-10 minutes.
Add to a 13x9-inch casserole or baking dish and set aside.
In a large bowl, whisk together eggs, milk of choice, and seasonings. Stir in chopped veggies.
Pour mixture over sausage. (Feel free to sprinkle on some shredded cheese, if desired!)
Bake until firm and cooked through, 30-40 minutes.
Allow to cool slightly before slicing into squares, serving, and enjoying!
Store leftovers in the fridge for up to 5 days, and reheat individual portions in the microwave.
Yields 12 servings (depending on size of cut).