1. Mix spice paste, tomato paste, and lemon juice. Coat shrimp with mixture.
2. Lay 2 or 3 shrimp flat, parallel to each other, and run 2 skewers about 1 inch apart through center of shrimp. Repeat to skewer remaining shrimp.
3. Lay shrimp on a lightly oiled grill over hot coals or high heat on a gas grill (you can hold your hand at grill level only 2 to 3 seconds). Cook, turning occasionally, until shrimp are opaque but moist-looking in center of thickest part (cut to test), 5 to 6 minutes. Serve hot or at room temperature.