Brown and crumble ground beef in a large skillet over medium-high heat. Drain if necessary. Add the packet of taco seasoning and 3/4 cup water. Bring to boil. Reduce heat and simmer 5 minutes, stirring occasionally until most of the water has evaporated. Set beef mixture aside.

Spread about 1/3-cup of the beans onto each of 6 tortillas. Top each bean tortilla with some of the beef mixture, dividing the beef evenly between the tortillas. Spread the beef evenly over the beans. Top each bean and meat tortilla with a plain tortilla.

Preheat oven to 500°F.

Heat a skillet or griddle over medium-high heat. Place pizzas in a large nonstick skillet one at a time and cook for 3-5 minutes or until golden brown. Carefully flip the pizzas over and cook an additional 3-5 minutes or until golden brown. Remove the pizzas to a large baking sheet. Repeat with remaining pizzas.

Top each pizza with enchilada sauce. Sprinkle with 1/3-cup cheese. Top with tomatoes, green onions and black olives. Bake pizzas for 3-5 minutes or until the cheese is melted and the pizza is heated through.

To serve, slice pizza into fourths with a pizza cutter. Serve with sour cream, if desired.