Position rack in bottom third of oven and preheat oven to 500 degrees F.
In a food processor, finely chop mushrooms, yellow onion and garlic.
Heat a large non-stick skillet over medium-high heat. Add beef and steak spice and cook, stirring and breaking up meat with a wooden spoon, for 8 minutes or until meat is no longer pink and no liquid remains in bottom of pan. Add mushroom mixture and cook, stirring frequently, until mixture is fragrant and liquid is evaporated. Transfer to a large bowl. Stir in Worcestershire sauce and season with salt and pepper.
Line a large (about 11- 16-inch) baking sheet with parchment paper, mist with cooking spray and sprinkle with cornmeal. Stretch dough to fit sheet.
Mix tomato and BBQ sauces together and spread in an even layer onto pizza dough. In a bowl, combine the cheddar and mozzarella, then sprinkle half the cheese mixture overtop the sauces. Spread beef mixture over cheese. Top with remaining cheeses, red onion, tomatoes and bacon.
Bake for 12 to 15 minutes, until crust is golden and cheese is golden brown.
While pizza is baking, combine yogurt and mustard. To serve, slice pizza, drizzle with yogurt sauce and top with shredded lettuce.
"Dish Do-Over" by Joanne Lusted (c) Harper 2014. Reprinted with permission from Harper. All rights reserved.