Heat oven to 375°F. Prepare biscuits as directed on can; cool slightly. Cut each biscuit into quarters; set aside. Decrease oven temperature to 350°F. Grease 2 1/2-quart baking dish.
In large skillet, heat oil over medium heat. Add onions; cook and stir until tender. Add mushrooms; cook until mushrooms just begin to brown. Add sausage, garlic, red bell pepper and seasoning; cook 3 minutes, stirring constantly. In large bowl, combine biscuit quarters and sausage mixture; mix well.
In medium bowl, beat eggs and milk until smooth. Pour over sausage mixture. Add cheeses; mix well. Spoon into greased baking dish.
Bake at 350°F. for 35 to 45 minutes or until firm.