Instructions

  1. Spray a 9x13 casserole dish with non-stick cooking spray.
  2. Lay the portabella mushrooms on the bottom of the casserole dish.
  3. In a separate bowl, mix together the first 9 ingredients and 1/2 of the cheeses.
  4. Spread over mushrooms.
  5. Top with remaining cheese and bake in a preheated oven at 350 degrees for 1/2 hour.