In a large bowl, combine oil, lemon juice, garlic, and spices, then whisk together and set aside. Add the chicken thighs to the marinade and toss to coat thoroughly. Cover and refrigerate for at least 2 hours or up to overnight.
Preheat oven to 425F, then add the sliced onion to the marinade and toss to coat. Spread the chicken and onion onto a baking sheet and bake for 30 minutes or until chicken is cooked through. Let chicken rest for 5 minutes, then slice thinly.
Serve on warmed pitas with the yogurt sauce, tomatoes, lettuce, and cucumber if desired.
For the Yogurt Sauce:
Combine the yogurt, lemon juice, and garlic in a bowl, then whisk together and season with salt and pepper to taste.
To cut down on cleaning time, you can marinate the thighs in a Ziploc bag and line the sheet pan with tin foil.
When ready to slice, cut the thighs against the grain. This way, the thighs are tender as you cut through the fibers.
Always let the chicken rest before slicing. The 5 minutes is just long enough that the juices will redistribute throughout the chicken. If you cut the thighs too early, all the juices will run out onto your cutting board.
If you don’t want to heat up to the kitchen with the oven, you can grill the thighs and onions.
Do not overcrowd the sheet pan as it’ll cause the thighs and onions to steam and not roast. If your sheet pans are small, you can use two sheet pans instead.
Feel free to use yellow onion, sweet onion, or red onions for this recipe.
Once the internal temperature of the thighs reaches 165F, they are ready. Use an instant thermometer to check.