Greek Gyro Sandwich

Begin by placing the onion into a food processor and grind it into tiny pieces. Next, transfer the finely chopped onion to a piece of cheesecloth and extract as much liquid as possible. Then, place the onion in a large bowl.

Combine lamb, beef, garlic, oregano, cumin, marjoram, thyme, rosemary, black pepper, and salt with the onion in the bowl using your hands until everything is well blended. Cover the bowl with plastic wrap and refrigerate for a couple of hours to allow the flavors to meld together.

Preheat your oven to 325 degrees Fahrenheit (165 degrees Celsius).

Process the meat mixture in a food processor until it's finely chopped and crumbly, taking about 1 minute. Then, pack the meat mixture into a 7x4-inch loaf pan, making sure there are no air pockets. Place the loaf pan in a roasting pan and pour enough boiling water around it to cover halfway up its sides for a water bath.

Bake the meat mixture in the preheated oven until it reaches an internal temperature of at least 165 degrees Fahrenheit (74 degrees Celsius), which should take around 45 to 60 minutes. Check the temperature by inserting an instant-read thermometer into the center of the meat loaf.

Once cooked, remove any excess fat and let it cool down slightly.

Now, slice the meat loaf into thin pieces.

Spread 1 tablespoon of hummus onto each pita bread, followed by some slices of the gyro meat loaf, shredded lettuce, tomato slices, red onion slices, feta cheese crumbles, and finally 2 tablespoons of tzatziki sauce to complete each sandwich.