Step 1

Heat the oven to 500°F with racks in the upper- and lower-middle positions. Arrange the pita breads on 2 rimmed baking sheets; set aside.

Step 2

In a food processor, pulse the onion until finely chopped, about 5 pulses. Add the roasted peppers, tomato paste, paprika, cumin, pepper flakes, ½ teaspoon salt and 1 teaspoon black pepper. Process until smooth, about 10 seconds, scraping the bowl as needed. Add the beef and pulse just until incorporated, 3 or 4 pulses.

Step 3

Divide the beef mixture evenly among the pitas (about a scant ½ cup each) and spread over the rounds, leaving a ½-inch border around the edge. Bake until the pitas are golden brown on the edges and the meat is sizzling, switching and rotating the baking sheets halfway through, 8 to 10 minutes. Cool for a few minutes, then transfer to a cutting board and cut into wedges.