Preheat your oven to 400°F. Line a large, flat baking sheet with parchment paper or aluminum foil and set it aside.

Heat a large skillet over medium-high heat. Drop in the ground beef and cook for 5 to 6 minutes, using a firm wooden spoon or a potato masher to pulverize the meat into tiny, fine crumbles that mimic fast-food style taco meat. Thoroughly drain away any heavy pooling grease.

Pour the taco seasoning packet and ¼ cup of water straight into the skillet with the beef. Reduce the heat to low and let it simmer gently for 3 to 5 minutes until the liquid thickens and fully coats the meat matrix. Remove from heat.

In a small saucepan set over low heat, combine the refried beans with 2 to 3 tablespoons of milk. Stir continuously until the beans are warm, smooth, and spreadable. Softening their consistency ensures you can glide them across a delicate fried tortilla without snapping it.

Pour the canola oil into a separate medium skillet over medium-high heat until it shimmers.

Using tongs, lower one flour tortilla at a time into the hot oil. Fry for 30 to 45 seconds per side until it puffs up slightly and turns an even, pale golden color. Transfer the fried tortillas to a plate lined with paper towels to drain completely. They will continue to crisp as they cool.

To assemble the pizzas, place 4 of the fried tortillas flat on your prepared baking sheet.

Spread roughly 2 to 3 tablespoons of warm refried beans evenly across each base. Top the beans with a generous scoop of the seasoned ground beef.

Carefully set a second fried tortilla flat over the meat and bean layers, pressing down very gently to anchor it.

Spoon 2 tablespoons of the red enchilada sauce uniformly over the surface of the top tortilla, spreading it right up to the borders. Scatter a heavy handful of shredded cheese across the sauce, and drop a few diced tomatoes and green onions over the top.

Place the baking sheet on the middle oven rack and bake at 400°F for 6 to 8 minutes. The pizzas are finished the exact moment the cheese matrix is entirely melted, bubbly, and the outer edges of the tortillas look beautifully toasted.

Remove the sheet from the oven and let the pizzas sit undisturbed for 2 minutes. Use a pizza cutter to slice each Mexican pizza cleanly into quarters, garnish with optional sour cream or olives, and serve immediately while hot and crisp.