In a large skillet over medium heat, combine the Italian sausage and ground beef. Cook until browned and cooked through, breaking up the meat with a wooden spoon as it cooks, about 7-10 minutes.
Once the meat is cooked, drain any excess fat from the skillet. Stir in the tomato sauce, drained sliced mushrooms, dried oregano, and garlic salt. Allow the mixture to simmer for about 5 minutes.
Preheat your oven to 375°F (190°C). While the oven heats, prepare your hamburger buns or English muffins. Place them on a baking sheet and lightly toast them in the oven.
Spoon a generous amount of the meat mixture onto each bun or muffin half. Top each with a sprinkle of shredded cheese, allowing it to melt beautifully in the oven.
Place the assembled pizza burgers in the preheated oven and bake for about 10-12 minutes, or until the cheese is melted and bubbly.
Once your pizza burgers are ready, take them out of the oven and let them cool for a minute. Serve them warm with your favorite side dishes.
