Prep the aromatics:Add the onion and garlic to a small food processor and blend into a smooth pulp.
Mix the meat:Combine the ground chicken, onion pulp, all seasonings, greek yogurt and olive oil in a bowl. Mix until fully combined.
Shape the doner:Divide the mixture in 3. Place one portion on a sheet of parchment paper. Place another piece of parchment paper on top and flatten the meat mixture using a rolling pin. Repeat with the all portions.
Roll it up:Starting from the long side, fold the parchment over the meat and continue rolling until it forms a long, flat rope.
Bake:Place both parchment-wrapped rolls on a baking sheet and bake at 400°F for about 30 minutes or until cooked through.
Break it apart:Let the rolls cool slightly, then unroll the parchment and break the meat into strips or pieces.
Crisp it up:Squeeze a little lemon juice over the top, spread the meat out on the baking sheet, and return it to the oven until lightly golden and crisp.
Make the garlic sauce:Stir together all ingredients for the garlic sauce.
Serve:Enjoy the doner in a pita or bowl with lettuce, tomato, pickles, red onion, jalapeños, and plenty of garlic sauce or garlic yogurt.