Step 1

For the Shells: Fill a wok or Dutch oven with 2-3 inches oil and heat to 375°F over high heat. Pull off a 2-tablespoon-sized piece of masa and form into a ball. Press dough into a thin round between two sheets of plastic in a tortilla press or roll out using a rolling pin.

Step 2

Place masa in hot oil and let cook until it floats and puffs, about 10 seconds. Using a metal spatula carefully press middle of tortilla down to create a taco-shell shape and hold until form sets, about 10 seconds longer. Using the spatula, gently submerge one side of shell into oil and cook until crisp, 10-15 seconds. Repeat with other side. Remove shell from oil and allow to drain, then transfer to a paper towel lined sheet pan, season with salt to taste, and repeat with remaining masa.

Step 3

For the Filling: Heat oil in a 12-inch skillet over medium-high heat until shimmering. Add onions and cook until softened and beginning to brown around the edges, 5-7 minutes. Add jalapeños and garlic and cook until fragrant, about 30 seconds. Add chili powder, oregano, cumin, coriander, and chipotle powder and cook until fragrant, about 30 seconds. Add ground chuck and cook, breaking apart with a wooden spoon or potato masher, until browned throughout, about 5 minutes.

Step 4

Stir in chicken stock and diced tomatoes and bring to a boil. Reduce to a simmer and cook until liquid thickens, about 15 minutes. Stir in cilantro and lime juice and season with salt to taste.

Step 5

Spoon meat mixture into taco shells and top with lettuce, grated cheese, onion, tomato, and/or sour cream. Serve immediately.