Heat a large skillet over medium-high heat. Add 1 tsp vegetable oil and the diced onion. Sauté 2–3 minutes until softened. Add the minced garlic and cook 30 seconds until fragrant.

Brown beef

Add the ground beef to the skillet and break it up with a spoon or spatula. Cook 5–6 minutes until mostly browned.

Season and simmer

Stir in chili powder, cumin, paprika, oregano, salt, and black pepper. Add the tomato paste and the 1/4 cup broth (or water). Stir to combine, reduce heat to medium-low, and simmer 3–4 minutes until the mixture thickens and flavors meld. Taste and adjust salt if needed. Remove from heat and keep warm.

Pico de gallo & salsa

Combine the diced tomatoes, diced onion, chopped cilantro, minced jalapeño (if using), juice of 1 lime, and 1/2 tsp salt in a bowl. Mix and let sit 10–15 minutes at room temperature so flavors meld. This is both the pico and the salsa served on the side; if you prefer a smoother salsa spoon, process half the mixture briefly in a blender for a chunkier sauce, or leave fully chunky for pico.

Baja sauce

Whisk together mayonnaise, Greek yogurt (or sour cream), lime juice, minced chipotle (or chipotle paste), honey, garlic powder, and 1/4 tsp salt in a small bowl until smooth. Taste and adjust heat or sweetness. Refrigerate until ready to use.

Flatbread assembly & finishing

Preheat oven to 375°F (190°C) or heat a large skillet over medium heat if toasting on stovetop.

If using oven: place flatbreads on a baking sheet. Divide warmed taco beef evenly among the 4 flatbreads, spreading into an even layer leaving a 1/2" border. Sprinkle each with shredded cheddar (about 1/2 cup per flatbread). Bake 6–8 minutes until cheese is melted and edges are lightly crisp. If using skillet: warm each flatbread 1–2 minutes, top with beef and cheese, cover with a lid and let sit 2–3 minutes until cheese melts.

Remove flatbreads from oven or skillet. Top each with a generous handful of shredded lettuce, 2–3 tablespoons pico de gallo per flatbread, and a few pickled jalapeño slices to taste. Drizzle Baja sauce over each flatbread (about 1–2 tbsp each). Garnish with chopped cilantro if using.

Serve immediately with the remaining pico de gallo/salsa on the side for dipping or extra topping.