Add the meat to a large mixing bowl. Use clean hands to break it apart and crumble it as much as possible.
1 lb ground lamb
Add all of the other burger ingredients to the bowl, then mix together until everything is as evenly combined as possible. Clean hands work best!
2 tbsp plain bread crumbs, 1/2 yellow onion, 1 tbsp minced garlic, 1 tbsp dried oregano, 1 tsp dried rosemary, 1 tsp dried thyme, 1 tsp black pepper, 1/2 tsp ground coriander, 1/2 tsp ground cumin, 1/2 tsp salt
Divide the meat mixture into 4 evenish balls, then flatten them into round patties that're a tiny bit wider than the width of the buns.
Set a large skillet, or griddle pan, over medium heat. Once hot add the patties to it, working it batches if necessary to prevent overcrowding, and cook for 3-4 minutes per side until they're cooked through.
Remove the skillet from heat and top the burgers evenly with the crumbled feta. Cover and let rest for 2 minutes.
1/2 cup crumbled feta cheese
To assemble the gyro burgers add lettuce to the bottom buns, then add a burger patty to each.
4 brioche buns
Top each burger with onions, tomatoes (if desired), and a generous dollop of tzatziki sauce. Finish by adding the top buns.
thinly sliced red onion, green leaf lettuce, tzatziki sauce
Serve immediately and enjoy!