All ingredients are readily available at Tesco, Sainsbury’s, Waitrose, ASDA, and Morrisons. Grilled chicken breasts can be prepared fresh or purchased pre-cooked. Whole-wheat pita bread is found in the bakery section, while mixed lettuce, tomato, cucumber, and red onion are in the produce section. Feta cheese is available in the dairy aisle, and Greek yogurt and fresh dill can be found in the chilled and herb sections. Olive oil and lemon juice are in the pantry and produce sections.