Step 1

Add oil, onion, and ground beef to a cast iron skillet set over medium-high heat. Add salt, chili powder, cumin, chipotle, garlic powder, black pepper, oregano, and cayenne. Break beef apart with a spatula to mix in spices; cook until browned and crumbled into very small pieces, 5 to 7 minutes.

Step 2

Stir in tomato paste and water and return to a simmer. Reduce heat to medium-low and cook until most of the liquid has reduced, 15 to 20 minutes. Stir in jalapeno peppers and cook for 1 minute. Turn off the heat, taste, and adjust seasoning.

Step 3

Preheat the oven to 350 degrees F (175 degrees C).

Step 4

Stack up 2 or 3 corn tortillas at a time and use a 2-inch round pastry cutter to cut 4 small circles out of each stack, making 60 total. Place circles in a single layer, 1/2 inch apart, on sheet pans.

Step 5

Mix Monterey Jack and Cheddar cheeses together. Top each tortilla circle with cheese, using the pastry cutter to keep it from spilling onto the pan. Repeat with remaining tortillas and cheese. Top each with about 1 teaspoon taco beef and another teaspoon cheese.

Step 6

Bake in the preheated oven until cheese melts, about 3 minutes.

Step 7

Remove from the oven. Carefully fold each tortilla in half, being careful not to press out the filling. Allow to cool for a few minutes, then chill in the refrigerator until firm, about 20 minutes.

Step 8

Heat vegetable oil in a nonstick skillet over medium-high heat. Working in batches and adding more oil as necessary, pan-fry tacos until crispy and heated through and the edges are a bit caramelized, about 2 minutes per side. Transfer to a paper towel-lined plate to drain.