Start with 2.5 lbs boneless chicken thighs. Trim off any excess fat to the extent you'd like, completely optional. Add it to a large bowl.
Process 1 medium yellow onion in a food processor. Add it to the chicken.
Add the juice of 1 lemon, 2 heaping tbsp tomato paste, and 2 heaping tbsp greek yogurt.
Season with 3-4 pinches of salt, fresh cracked pepper, 1 tbsp thyme, 1 tbsp garlic powder, 1 tbsp urfa pepper (or Aleppo pepper or any other chili flakes).
Mix it super well, and ideally let this marinate for 2-6 hours, but even better overnight, but if you want to make it right away, you can.
Preheat your oven to 425F. Remove chicken from the fridge and let it come up to room temp (about 30 mins) before popping in the oven. then pack the marinated chicken tightly into a bread loaf pan (about 8.5x4.5x2.5). Pop it into the oven for 50 mins at 425F.
Remove the chicken from the oven, carefully tilt the pan onto a glass bowl or container to remove the excess juices. Pour the juices over the chicken, then tilt the pan again onto the glass bowl or container to remove the excess juices and set the juices aside.
Flip the chicken onto a cutting board and cut into thin slices or strips.
Serve it up however way you want - as is, on top of a salad, on a power bowl, whatever! This stays well in the fridge in an airtight lid for 4-5 days.