Preheat the oven to 350 degrees.
Use a large bowl and add the ground lamb, ground beef, onion, garlic, and olive oil. Add in all of the seasonings as well.
Use a large spoon, or your hands to fully combine this mixture. Once the ingredients are combined, add the meat mixture in small batches to a food processor or a blender.
Mix it up for about one to two minutes, or until the meat and all of the ingredients are finely minced. Remove it from the blender or processor and set it aside in a bowl. Continue adding the meat in batches until it is all finely minced.
Place the minced meat into a 9x5 loaf pan or 9x13 baking dish. Press it together firmly to shape it into a log-like rectangular shape. Be sure to PRESS OUT ALL OF THE AIR BUBBLES.
The meat mixture should be packed firm so no air bubbles remain. Place the dish in the oven and bake for 45-50 minutes. The internal temperature should read at least 165 degrees Fahrenheit.
Remove the gyro meat from the oven and reserve excess oil that accumulated.
After the meat rests for about 10-15 minutes, slice it very thinly. Optional: fry it in the oil that you reserved prior to serving.