Mix ground beef, onion, garlic, butter, lemon juice, panko, parsley, eggs, spices, salt, and pepper. Shape into 8–10 long patties and freeze for 30–60 mins.
Grill over medium-high heat, 4–5 mins per side, to 160°F. Rest before serving.
Mix yogurt, garlic, lemon juice, olive oil, dill, salt, and pepper. Chill 1 hour.
Toss cucumbers, tomatoes, red onion, oregano, olive oil, lemon juice, salt, and pepper. Chill 30 mins.
Warm naan, spread hummus (optional), add beef patties, tzatziki, cucumber salad, feta, crushed pita chips (optional), and fresh dill.