Prepare your filling: In a large nonstick skillet, heat the oil over medium-high. Add the beef and onion, season aggressively with salt and pepper, and cook, breaking into tiny pieces, until the beef starts to brown, about 5 minutes. Stir in the tomato paste, then the cumin, paprika, ancho chile powder and garlic powder, and cook, stirring occasionally, until fragrant and any excess liquid evaporates, about 3 minutes. Transfer the mixture to a medium bowl. Using a paper towel, wipe out the skillet.

Prepare the spicy sour cream: In a small bowl, mix together the sour cream and adobo sauce; season to taste with salt and pepper.

Prepare the assembly line: On a large flat surface, set out the flour tortillas. (You'll need your tortillas to be pliable without tearing, so if need be, you can warm them directly in the skillet over medium heat to soften just until soft and pliable.) Add ½ cup filling to the center of one tortilla, flattening the filling into an even, 4-inch circle just a bit smaller than the width of your tostadas. Spread with 3 tablespoons queso over the filling. Top the mixture with a tostada, pressing it slightly to make sure the meat mixture is evenly distributed. Evenly spread 2 scant tablespoons of the spicy sour cream on top of the tostada. Top evenly with a heaping ¼ cup shredded lettuce, then 3 tablespoons drained pico de gallo.

Enclose the filling by folding over one flap of the tortilla "border" to cover the filling, repeating the pleat every inch or two. The tortilla should fully enclose your filling, but an opening smaller than 1 inch at the center is just fine. (You can also use slightly less filling, or add a piece of tortilla to cover the gap; see Tip.)

Heat 1 tablespoon oil in the skillet over medium, then carefully add the wrap, setting it seam side down. Cook until golden and crisp, 2 to 3 minutes per side.

Serve immediately, with hot sauce and the remaining spicy sour cream, for dipping or slathering as you eat, dousing the wrap bite by bite. Repeat with remaining wraps, adding oil as needed to the pan before searing.