1. In a large bowl, combine egg substitute, milk, garlic salt, asparagus, and cheese. Mix well.
2. Spray 10" skillet with cooking spray and heat over medium. Saute onion, pepper, and asparagus until tender (5-8 minutes).
3. Reduce heat to low and pour egg mixture into skillet. Cover and cook until set (15-20 minutes).
4. Cut into slices to serve.