1/4-1/2cupFresh herbsParsley, cilantro, dill, mint, any combo you like. Use as many as you like.
Mix garlic, oil, curry powder, 1 cup yogurt, 2 tsp. salt, and 1/4 cup water in a large bowl. Working in batches, add chicken thighs and turn to coat, using your hands to rub marinade under skin of each thigh. Transfer to a resealable plastic bag and chill at least 3 hours or up to overnight.
Heat one side of grill on high, and one side to low. Grill chicken skin side down on high until brown, turn and brown the other side. Move chicken to low heat, cover and cook until done, turning often so it doesn't burn. Chicken thighs will take about 30 minutes, breasts, 20. It all depends on how large the pieces are, of course, so you'll need to adjust your grilling times until juices run clear. Move to platter and cover for 10 minutes before serving.
Preheat to 425°F. Transfer marinated chicken, skin side up, to a 13x9" baking dish. Roast chicken until skin is browned and an instant-read thermometer inserted into the thickest part of chicken registers 165°F, about 35 minutes. If chicken skin starts to burn, cover with foil to finish cooking.
Transfer chicken to a serving platter, reserving pan juices. Whisk lemon juice, 1/4 cup pan juices, remaining 1 cup yogurt, and remaining 1/2 tsp. salt in a medium bowl. If sauce is too thick, add more pan juices. Serve sauce alongside chicken.
Chicken can marinate up to 1 day before cooking. Keep chilled.
While chicken is cooking, make sauce. Add rest of yogurt, lemon juice, herbs, lemon juice to a bowl and mix. Add salt and pepper to taste. You can keep it plain, or add 1 tsp of curry powder if you would like more spice. Make this ahead and keep in fridge until ready to serve.
Chicken can marinate up to 1 day before cooking. Keep in the fridge.
You can add cucumber, finely chopped to the sauce.