Make tahini sauce: Whisk together tahini, 1/4 cup water, lemon juice, garlic, cumin and 1/2 tsp. salt.
Make lamb: Sprinkle chops on both sides with salt. Warm vegetable oil in large skillet over medium-high heat. Add chops and sauté until browned on both sides, about 10 to 15 minutes total for medium-rare. Drizzle chops with tahini sauce and serve.