Heat 2 tablespoons of the olive oil in a fry pan over medium heat, reserving the balance. Cook the onions until they caramelize.
Preheat oven to 400 degrees F. Spread 1 tablespoon of the remaining olive oil over each of the 2 pizza shells. Spoon 1/4 cup of the hot sauce over each of the pizza shells. Lay out 1 package of chicken nuggets on each pizza shell. Distribute the caramelized onions over the 2 pizzas. Sprinkle the Monterey jack cheese and mozzarella cheese over the pizzas. Drizzle ranch and blue cheese dressings over the pizza toppings and bake for 10 minutes or until cheese is melted and chicken is heated through.