Preheat oven to 425°F
In a large bowl, combine the beef, lamb, onion, garlic, yogurt, and spices. Mix aggressively for 3–4 minutes until it turns into a paste
Divide into 4 portions. Place one portion between parchment paper, roll it out flat, then roll it into a log
Place on a sheet pan and bake for 15–18 minutes until cooked through
While the meat bakes, make your salad and tzatziki. Mix all ingredients for each and let sit until ready to use
Let the meat cool slightly, then slice thin. Spread on a sheet pan and broil for 3–5 minutes until browned and crispy
Serve in warm pita or naan with salad and tzatziki, and top with feta cheese if using
