Heat oven to 425°F, then line a baking sheet with parchment paper so the soft taco for 2 tortillas won’t stick and are easy to remove after baking.

Prick the soft taco for 2 tortillas all over with a fork, then brush both sides with vegetable oil. Cook one or two tortillas at a time in a large skillet over medium heat until lightly browned, 30 to 45 seconds total, flipping halfway through so both sides brown evenly. Transfer each browned tortilla to the prepared baking sheet and repeat with the remaining vegetable oil and tortillas.

In the same or a clean skillet, cook the lean ground beef over medium-high heat, stirring with a wooden spoon to crumble it into small pieces. Continue cooking until the beef is browned, about 2 minutes, and cooked through with no longer pink bits remaining. Stir in the taco spice, then transfer the seasoned beef to a small plate so it’s ready for assembling.

Arrange three of the browned soft taco for 2 tortillas on the parchment-lined baking sheet. Divide and spread the black bean refried beans evenly over each tortilla, then top each with some of the seasoned lean ground beef mixture and 1 tbsp of shredded monterey jack or cheddar cheese. Place another browned tortilla on top of each to form a stack. Divide and spread the pizza sauce over the top tortillas, then sprinkle with the remaining shredded monterey jack or cheddar cheese, covering the surface so it will melt evenly.

Bake the assembled Mexican pizzas at 425°F until the cheese is melted and bubbling, about 5 minutes, and the pizzas are heated through and piping hot. Remove from the oven and immediately top each with shredded iceberg lettuce, cherry tomatoes, and thinly sliced red onions before serving.