Lamb:
1 tablespoon olive oil
2 pounds ground lamb
Kosher salt and freshly ground black pepper
1/2 red onion, minced
1 teaspoon dried oregano
4 cloves garlic, minced
1 tablespoon tomato paste
2 tablespoons dry red wine

Feta Mint Tzatziki:
1 English cucumber
Salt
1 cup whole-milk Greek yogurt
1/2 cup crumbled feta cheese
1 clove garlic, minced or pressed
2 tablespoons minced fresh mint

Cucumber Tomato Relish:
1 tablespoon extra-virgin olive oil
1 tablespoon red wine vinegar
2 firm tomatoes, seeded and diced
1 English cucumber, seeded and diced
1/2 red onion, diced
Freshly ground black pepper

Sandwich Build:
4 non-pocket pitas, oiled and lightly griddled on each side