Step 1

To make the raita: In a medium bowl, mix together yogurt, cucumber, mint, cumin, salt, and cayenne pepper. Place in refrigerator for at least 2 hours, and up to three days, to chill and let flavors meld.

Step 2

To make the chicken: In a large bowl, whisk together yogurt, lemon juice, garlic, ginger, cumin, paprika, salt, coriander, turmeric, annatto powder, and cayenne pepper. Place chicken in marinade, cover, and refrigerate 4 to 8 hours.

Step 3

Thread chicken onto skewers so each piece is just barely touching the next.

Step 4

Light one chimney full of charcoal. When all charcoal is lit and covered with gray ash, pour out and spread the coals evenly over entire surface of coal grate. Set cooking grate in place, cover grill and allow to preheat for 5 minutes. Clean and oil the grilling grate. Grill chicken, turning occasionally, until well browned on all sides and center of meat registers between 150-155°F on an instant read thermometer, about 10 minutes total. Transfer skewers to platter and let rest for 5 minutes. Serve immediately with red onions, cilantro, and raita.