Saute Sausage until good and brown, drain. Add onions, chilies, mushrooms. Stir fry 1 minute. Mix eggs, sour cream and seasonings. Beat until well blended. Pour this into a 9 x 9 pan. Bake this at 400°F until eggs are soft and set. Remove from oven and put meat mixture on top. Top with both cheeses. Broil until cheese melts. Let set for a few minutes. Cut and serve with salsa.