Pat the chicken breast dry with paper towels and drizzle it lightly with olive oil. Season both sides evenly with garlic powder, onion powder, dried oregano, salt, and freshly ground black pepper. Let the chicken rest for 10–15 minutes so the seasonings absorb into the meat before cooking.

Heat a grill pan, skillet, outdoor grill, or air fryer over medium-high heat. Cook the chicken for approximately 5–7 minutes per side, or until the internal temperature reaches 165°F (74°C). Transfer the cooked chicken to a cutting board and let it rest for at least 5 minutes before slicing it into even strips.

Wash the cucumber and cherry tomatoes thoroughly under cold running water. Dry them completely with a clean kitchen towel or salad spinner. Cut the cucumber into bite-sized chunks and leave the cherry tomatoes whole or slice them in half if preferred.

Spoon the tzatziki into a small reusable dressing container or the sauce compartment of your meal prep container. Keeping the sauce separate helps maintain the crisp texture of the vegetables until you're ready to eat.

Arrange the sliced grilled chicken neatly in one compartment of the meal prep container. Add the cucumber chunks and cherry tomatoes beside the chicken, keeping the ingredients separated for the freshest presentation.

Sprinkle the crumbled feta cheese evenly over the cucumber and tomatoes. If desired, garnish with freshly chopped dill, parsley, or a lemon wedge for additional Mediterranean flavor.

Seal the meal prep container tightly with its lid and refrigerate until ready to eat. Serve the tzatziki on the side for dipping, or drizzle it over the chicken and vegetables just before enjoying for the freshest taste and texture.