Steak Pizza with Blue Cheese

Name: Steak Pizza with Blue Cheese
Ingredients: dough for one 12- to 13 pizza, parbaked at 475 for 6 minutes, or one prepared pizza crust; 1 large onion, sliced thin; 2 Tablespoons olive oil, divided; salt and pepper to taste; pinch sugar; 8 oz. thinly sliced mushrooms; 2 teaspoons Worcestershire sauce; 10 ounces leftover grilled steak, sliced thinly across the grain; 1 cup shredded monterey jack cheese; 12 cherry tomatoes (or two regular tomatoes), thinly sliced and drained on paper towels (I used red and yellow tomatoes); ¼ cup blue cheese crumbles