In a large bowl, combine ground beef, salt and pepper and garlic powder until thoroughly blended. Divide meat into 8 equal portions. Make into 8 burgers. Set in refrigerator until stuffings are done.
In a skillet combine-mushrooms, onion, and butter over medium heat and cook until onion and mushroom ca1melize. Set aside to cool.
Toke one burger and make a dent in the center and place a tablespoon of mushrooms into dent. Cover mushrooms with rest of burger and shape into a ball, making sure stuffing is not showing. Flatten burger. Repeat process 3 more times. Stuff the next 2 burgers with crumbled blue cheese and last 2 burgers with a teaspoon of salsa. In a skillet, over medium-high heat, place burgers, and let cook 1mtil cooked clear through, turning only once. Place slice of cheese on top of burger just before serving. Place on toasted roll and serve with condiments*: Makes 8 servings. Enjoy!
*CONDIMENTS FOR BURGERS: Ketchup, mustard, mayonnaise, relish, chopped onion, salsa, sliced tomatoes, lettuce, sliced avocado, etc...