Preheat the oven to 500 degrees . In a small bowl, combine the yogurt and two-thirds of the garlic; season with salt and pepper.
In a large skillet, heat the olive oil over medium heat. Add the bell pepper and onion and cook, stirring occasionally, until softened, about 5 minutes. Stir in the remaining garlic, the habanero chile and cumin; cook until fragrant, about 30 seconds. Add the beef and cook, breaking up with a spoon, until no longer pink, about 5 minutes; season with salt and pepper.
On a baking sheet, top each pita with a quarter of the beef mixture and bake until crisp, about 8 minutes. Serve with the garlic yogurt.