You can use any cut of chicken you like with this recipe (whole chicken cut into pieces, thighs, etc.). I prefer boneless, skinless chicken breasts.
Whisk together the 1/2 cup yogurt, lemon zest, the juice from 1/2 lemon, olive oil, 4 cloves crushed garli, garlic, paprika, herbes de Provence, 1 teaspoon salt, and black pepper in a bowl. Pour into a resealable plastic bag. Add chicken, coat with the marinade, squeeze out excess air, and seal the bag. Marinate in refrigerator for at least 3 hours.
Preheat an outdoor grill for medium-high heat, and lightly oil the grate.
Combine 1/2 cup yogurt, 1 tablespoon lemon juice, Sriracha, 1 crushed garlic clove, cumin, coriander and 1/2 tsp. salt in a small bowl. Set aside.
Remove chicken from bag and grill chicken, on the preheated grill for 2 minutes. Turn each piece and move to indirect heat.
Grill, turning often, with lid down until well-browned and meat is no longer pink in the center. An instant-read thermometer inserted into the thickest part of the thigh, near the bone should read 165 degrees F (74 degrees C).
Serve chicken with the yogurt sauce on the side.