2 cups plain nonfat yogurt
4 large cloves garlic, peeled, roughly chopped
2 tsp ground ginger
2 tsp tandoori masala (or garam masala)
2 tsp ground cumin
1 tsp ground coriander
1/2 tsp hot curry powder
1 tsp honey
2 tsp olive oil
Juice of 1/2 lemon
1 tsp kosher salt
1/2 tsp fresh black pepper
3-4 lb boneless turkey breast, skin removed, butterflied
In a large bowl, mix together all ingredients except the turkey, and stir well to combine. This is the marinade.
Dunk the turkey breast in the yogurt marinade, turning it over and over to coat all of the surfaces of the meat. Cover the bowl tightly with plastic wrap, and refrigerate for at least 6 hours or overnight.
When you're ready to cook, heat a grill on high heat. Shake off excess marinade, and set the turkey flat on the grill (make sure to "open" all of the flaps of the meat).
Grill for 10 minutes. Turn, and cook for an additional 8 minutes. The meat should be firm to the touch, but the easiest way to tell if it's done is to remove it from the grill and make a small cut in the thickest part of the meat. Or, use an instant-read thermometer to check that the internal temperature of the thickest part of the meat is 165°F (the turkey will continue to cook off the grill to 170°F).
Remove the turkey from the grill and set it on a tray. Cover with aluminum foil. Let sit for 15 minutes before slicing. Serve warm, at room temperature, or cold.