If serving as a main dish rather than in a pita, you may wish to use more chicken.
In a large bowl mix the yogurt, garam masala, ginger, garlic, and salt. If you’re looking for a little heat, add the optional cayenne. Add the chicken. Set aside at room temperature for 30 minutes or cover and refrigerate for up to 24 hours.
When ready to cook, place one rack in the center of the oven, the other in the top position; preheat the oven to 425°F. Spray a large sheet tray liberally with cooking spray or line with parchment. Arrange chicken, after removing excess marinade mixture, on the sheet tray. Discard any leftover marinade mixture.
Place the sheet tray on the middle rack in oven and roast for a total of 15 to 20 minutes, turning chicken over once, until close 160 degrees F. Move the tray to the top rack and turn the broiler on until chicken is nicely browned and/or lightly charred in spots. Note: it’s best to sacrifice color than to cook too long and have dry chicken. Watch it carefully towards the end.
Remove chicken from sheet tray and serve with lemon wedges and desired accompaniments.