Preparation

• Mix the cumin, curry powder, salt, garlic powder, ginger, and cayenne in a medium bowl. Heat the oil in an 8-inch skillet over low heat. Stir the spices into the oil and heat until they bubble and become fragrant, 30 to 60 seconds. Return the spice blend to the bowl and stir in the vinegar and then the yogurt. Add the chicken thighs and toss to coat evenly. Let sit 10 min. or cover and marinate in the refrigerator for up to 12 hours.
• When ready to cook, prepare a hot charcoal fire or heat a gas grill with all burners on medium high for 10 min. Clean the hot grate with a wire brush and then lubricate it with an oil-soaked paper towel. Put the chicken on the grate and grill (covered on a gas grill or uncovered over a charcoal fire) until one side has dark grill marks, 5 to 6 min. for large thighs or 4 to 5 min. for medium and small thighs. Turn and continue to grill until well marked on the other sides and cooked through, 5 to 6 min. longer for large thighs or 4 to 5 min. for medium and small thighs. Move the thighs to a platter and let rest 4 to 5 min. Sprinkle with chopped cilantro before serving.

To prepare as kebabs: Trim the thighs and then slice them lengthwise into 1-1/2- to 2-inch-wide strips. Toss with the flavorings; then thread the chicken onto six 8- or 12-inch skewers (soak wood skewers in water for at least 20 min. first), folding each strip in half as you skewer it. If some strips are very thick, cut them in half crosswise rather than folding them so that all the pieces of chicken are roughly the same size. Grill the kebabs, turning them every 4 to 5 min. as dark grill marks form, until cooked through, 12 to 15 min. total