Whisk together minced garlic, oregano, lemon juice, olive oil, salt, and pepper to make the marinade. Place boneless lamb shoulder in a shallow dish and pour marinade over, turning to coat all sides evenly. Cover and refrigerate for 4 to 24 hours, preferably overnight.
4 cloves garlic, 2 tbsp dried oregano, 0.25 cup lemon juice, 3 tbsp olive oil, 1 tsp salt, 0.5 tsp black pepper, 2 lbs lamb shoulder
Preheat oven to 375°F (190°C). Transfer lamb and marinade to a roasting pan or sheet pan. Roast for 40 to 45 minutes, or until a meat thermometer inserted into the thickest part reads 145°F (63°C). Increase oven temperature to 425°F for the last 5 minutes to crisp the edges.
2 lbs lamb shoulder
Remove lamb from oven and tent loosely with foil. Let it rest for 10 minutes to allow juices to redistribute. Then slice the lamb thinly into strips about ⅛ inch thick using a sharp knife.
2 lbs lamb shoulder
Grate the cucumber and squeeze excess water out using a kitchen towel. In a bowl, mix drained cucumber with Greek yogurt, 1 minced garlic clove, 1 tablespoon lemon juice, and salt to taste. Chill until ready to serve.
1 whole cucumber, 1 cup Greek yogurt, 1 clove garlic, 1 tbsp lemon juice, to taste salt
Warm pita breads in a 350°F oven for 1 to 2 minutes until pliable. Fill each pita with sliced lamb, tomato slices, onion slices, and a generous spoonful of tzatziki sauce. Fold and serve immediately.
4-6 pita breads pita bread, 2 lbs lamb shoulder, 2 whole tomatoes, 1 small onion, 1 cup Greek yogurt