In a skillet over medium-high heat, add ground beef and cook until it begins to brown.
Add onions to skillet and continue to cook until meat is cooked through.
Drain any excess grease from the meat and return to skillet before adding the taco seasoning and ¼ cup of water. Continue to cook, stirring together, until water cooks away. Set taco meat aside.
In a large skillet over medium-high heat, spray the skillet with cooking spray and cook each tortilla until it begins to crisp slightly, approximately 1 minute per side. Set aside.
Preheat oven to 400℉.
Place a tortilla on your baking sheet and add one layer of refried beans, and one layer of taco meat.
Place the other tortilla on top and spread enchilada sauce over the top and top with shredded cheddar cheese.
Continue this process with the rest of the tortillas.
Place the baking sheet in the oven and bake for 5-7 minutes, until cheese is melted.
Remove from the oven and top with your favorite fresh ingredients.
Cut into 4 slices and serve.
Most likely, only 2 Mexican Pizzas will fit side-by-side on your baking sheet, so you will have to bake these in batches, two at a time.