In a large skillet over high heat, melt butter. Add sliced mushrooms and cook for 2-3 minutes or until browned.
Add red pepper, hot pepper sauce, and salt. Cook 2 minutes.
Heat grill (or grill pan) on medium heat.
Sprinkle steaks on both sides with garlic powder and lemon-pepper seasoning.
Grill 8-10 minutes, turning once for medium-rare.
Spoon warm spicy mushrooms over steaks prior to serving.