Mix the ground beef, onion, garlic, butter, lemon juice, panko, parsley, eggs, oregano, cumin, chili powder, thyme, salt, and pepper in a bowl
Shape into 6-8 oval patties and freeze for 20 minutes to firm
Grill over medium-high heat for 4-5 minutes per side until internal temperature reaches 160°F and let rest
Stir together the yogurt, garlic, lemon juice, olive oil, and dill for tzatziki sauce
Season tzatziki with salt and pepper
Toss the cucumbers, tomatoes, red onion, oregano, olive oil, and lemon juice for the salad
Season cucumber salad with salt and pepper
Warm naan or pita bread
Assemble gyros by adding grilled beef, tzatziki, cucumber salad, feta, and optional hummus or pita chips to the warm bread
