I have not made this yet. But, it is on the menu for this week.
Gyro meat: 1 med onion, 2 lbs ground lamb or beef, 1 tbsp minced garlic, 1 tbsp dried rosemary, 1 tbsp dried marjoram, 2 tsp kosher salt, 1/2 tsp pepper -- Process onion in food processor 10-15 sec. Squeeze out all juice using a tea or paper towel. Return onion to food processor and add meat, garlic, and spices and process until it is a fine paste - about a minute - scraping as needed. Cook in the oven in meatloaf form - 325 deg for 60-75 min (internal temp of 165 to 170) - thinly slice when done and serve in pita bread.
Tzatziki sauce: 16 oz plain yogurt, 1 med cucumber peeled, seeded and finely chopped, 4 cloves garlic, minced, 1 tbsp olive oil, 2 tbsp red wine vinegar, 5-6 minced mint leaves, pinch kosher salt. Drain yogurt over a tea towel for 2 hours in the fridge. Place cucumber in a tea towel and squeeze out liquid. In a medium bowl, combine the yogurt, cucumber, olive oil, salt, garlic, vinegar and mint. Stir well - can keep in fridge for up to a week.