Tandoori masala is a spice mixture that includes coriander, cumin, ginger, fenugreek, and pepper.
Whisk together all ingredients except shrimp and sesame seeds in a large nonreactive bowl. Add shrimp; stir to coat. Cover; refrigerate, and let marinate, tossing shrimp occasionally, 2 to 3 hours.
Heat a large skillet over medium-high heat until hot. Cook shrimp in batches (do not crowd skillet), turning once, until pink and cooked through, about 4 minutes per side. Transfer to a plate. Repeat with remaining shrimp. Discard marinade. Sprinkle shrimp with sesame seeds.
Tandoori masala is available at specialty-food shops and Indian markets.
