Turkish Shish Kebabs With Garlicky Tahini

Name: Turkish Shish Kebabs With Garlicky Tahini
Ingredients: 6 garlic cloves, crushed; 3 tablespoons extra-virgin olive oil, plus more for brushing; 3 tablespoons fresh lemon juice; 1 teaspoon kosher salt; 1 teaspoon freshly ground pepper; 1 teaspoon dried mint; 1 teaspoon dried oregano; 1 1/2 pounds trimmed boneless leg of lamb, cut into 1 1/2-inch cubes; 1 small bunch of fresh mint; 1 large red onion, cut into 2-inch pieces; 1 large yellow bell pepper, cut into 2-inch pieces; 1 large green bell pepper, cut into 2-inch pieces; Vegetable oil, for the grill; Garlicky Tahini; Lemon wedges and pita bread, for serving