Heat the oven to 350F and grease a 7x11 pan.
In a large bowl, whisk the eggs with the sour cream, milk, cheddar, salt and pepper until just combined.
Brown the sausage in a large skillet over medium heat, breaking it up as it cooks. Drain off most of the grease and stir the sausage into the egg mixture.
In the same skillet, saute the peppers and green onions 2-3 minutes, then stir them in too.
Pour into the pan and bake 30-40 minutes, until the edges are set and the center is barely jiggly.
Leftovers keep 3-4 days in the fridge and reheat fine in the microwave.