Butter English muffins and place buttered side down in 9x13 inch pan. Fry sausage until pink is gone. Keep sausage broken in bits and drain on paper towels. Sprinkle over English muffins.
Beat eggs together with sour cream. Blend in most of the Colby and Monterey Jack cheeses, but leave enough to sprinkle on top of the casserole. Pour mixture over sausage layer and spoon in the 2 cans of chilies. Sprinkle top of chilies with remaining cheese.