Trim excess fat from chicken thighs and pat them dry with paper towels. Cut each thigh into 1 to 1-1/2 inch cubes so they will thread onto skewers and cook evenly.

Make marinade

In a medium bowl combine yogurt, olive oil, lemon juice, minced garlic, cumin, coriander, smoked paprika, black pepper, kosher salt, and red pepper flakes (if using). Whisk until smooth and fully combined.

Marinate chicken

Add the chicken pieces to the marinade and toss until every piece is coated. Cover the bowl and refrigerate for at least 1 hour, ideally 3–6 hours. For best flavor and tenderness, marinate up to 12 hours. If short on time, 30 minutes will still add flavor.

Skewers & Finish

Soak wooden skewers (if using)

If using wooden skewers, submerge them in cold water for at least 20–30 minutes before grilling to prevent burning.

Thread chicken onto skewers

Remove chicken from the refrigerator. Thread 4–6 pieces of chicken onto each skewer, leaving a small gap between pieces so heat circulates and they cook evenly. If using metal skewers, space similarly.

Preheat grill or broiler

Preheat an outdoor grill to medium-high (about 400°F / 200°C). Alternatively, preheat the oven broiler to high and position a rack 6 inches from the element. Lightly oil the grill grates or prepare a foil-lined baking sheet if broiling.

Cook the skewers

Brush the skewers lightly with the extra olive oil. Place skewers on the hot grill or under the broiler. Grill for 3–4 minutes per side, rotating every 3–4 minutes, for a total of 10–12 minutes, until the internal temperature reaches 165°F (74°C) and the exterior is nicely charred. If pieces are larger or the grill is hotter, adjust time accordingly. For thicker pieces you may need 12–14 minutes.

Rest and finish

Transfer cooked skewers to a cutting board and let rest for 5 minutes. Sprinkle chopped parsley over the skewers and serve with lemon wedges for squeezing over the chicken.