- Preheat oven to 425 °F.
- Coat large skillet with nonstick spray, and heat over medium heat until hot.
- Add mushrooms, squash and onion, and cook, stirring often, until softened, about 8 minutes.
- Stir in black beans, basil, thyme, garlic powder, salt and pepper, and cook.
- Cover, and remove from heat.
- Spray 9-inch deep-dish pie plate with nonstick cooking spray.
- Add margarine, and heat in oven until margarine has melted.
- In medium bowl, whisk together flour, milk and eggs.
- Pour mixture into pie plate, and bake 12 to 15 minutes, or until crust is puffed and brown.
- Spoon mushroom mixture into crust, and top with cheese.
- Bake 7 to 10 minutes, until cheese is melted.
- Serve warm.