Add beef to the slow cooker.
Combine ¼ cup olive oil, garlic, oregano, salt,pepper and lemon juice in a small bowl. Pour over the meat and toss to coat, in the slow cooker. Toss in the sliced onions.
Cover and cook on LOW for 6-10 hours (depending on your slow cooker) or until beef is extremely
Tender. (If it’s not tender, it’s not done yet).
Remove lid and salt and pepper to taste. If desired, break up the meat into smaller bite-size pieces.
Make the tzatziki sauce. Combine yogurt, cucumber, dill, salt and garlic in medium bowl. Stir until creamy and combined. Salt and pepper to taste.
Serve beef over pita folds with Tzatziki sauce, onions, tomatoes and lettuce.
