In a large bowl, mix together all the spices (paprika, turmeric, garlic salt, salt, coriander, cardamom, cloves, cinnamon, allspice, cayenne, and onion powder), the chopped onion, garlic, olive oil, Greek yogurt, and lemon juice to create the marinade.

Toss the chicken thighs in the marinade, ensuring all pieces are well coated. Cover and refrigerate for at least 4 hours, or overnight for best results.

If using vertical skewers, thread the marinated chicken thighs onto the skewers. Use half an onion to secure the top of the skewer. Place the skewers upright on a baking sheet and cook at 400°F on the lower oven rack. Rotate the skewers every 20 minutes until the internal temperature of the chicken reaches 165°F (about 45 minutes).

If using regular skewers, cut the marinated chicken into 1-inch pieces and thread them onto the skewers. Place the skewers on a baking sheet and cook at 400°F on the middle rack, flipping halfway through. Cook until the internal temperature reaches 165°F (about 25-30 minutes).

If youʼre not using skewers, simply lay the marinated chicken thighs flat on a baking sheet. Cook at 400°F on the middle rack, flipping halfway through, until the internal temperature reaches 165°F (about 25-30 minutes).