How to Make It
Preheat the oven to 425°. Arrange the pita breads on a parchment paper–lined baking sheet. In a medium bowl, combine the ground beef, onion, bell pepper, tomato paste, pistachios, parsley, cumin, oregano, allspice, half of the garlic and the 1/4 teaspoon of salt. Spread the meat mixture on the pitas in an even layer. Bake for about 8 minutes, until the meat is browned in spots and cooked through.
In a small bowl, mix the yogurt with the lemon juice and remaining garlic. Season with salt. Serve the flatbreads with the garlicky yogurt and pickled vegetables.