Spicy Lamb and Lentils with Herbs

Name: Spicy Lamb and Lentils with Herbs
Ingredients: 1 tablespoon vegetable oil; ½ pound ground lamb; Kosher salt and freshly ground black pepper; 2 garlic cloves, thinly sliced; 1 teaspoon crushed red pepper flakes; ½ teaspoon cumin seeds; 1½ cups cooked brown or French green lentils (from 1 cup dried); ½ English hothouse cucumber, chopped; ½ cup chopped fresh cilantro, plus leaves for serving; ¼ cup chopped fresh parsley, plus leaves for serving; ¾ cup plain whole-milk Greek yogurt; Flatbread and lemon wedges (for serving)