Cook the chicken using your preferred method—grill, bake, air fry, or pan-sear—until it reaches an internal temperature of 165°F (74°C). If grilling or pan-searing, cook over medium heat for about 5–7 minutes per side, depending on the thickness. For baking, place the chicken in a 400°F (200°C) oven for 20–25 minutes. If using an air fryer, cook at 380°F (193°C) for 14–18 minutes, flipping halfway through. Once fully cooked, transfer the chicken to a cutting board and let it rest for 5–10 minutes before dicing it into bite-sized cubes. Resting the chicken helps lock in the juices, keeping every piece tender and flavorful.

While the chicken is resting, prepare the vegetables. Wash the cucumber, cherry tomatoes, celery, parsley, and red onion thoroughly under cool running water. Dry everything well with a clean kitchen towel or paper towels, as excess moisture can make the salad watery. Dice the cucumber and celery into small, even pieces, halve the cherry tomatoes, finely chop the red onion, and roughly chop the fresh parsley. Keeping the vegetables similar in size ensures every bite has a perfect balance of flavors and textures.

In a medium mixing bowl, prepare the creamy cottage cheese dressing. Add the cottage cheese, fresh lemon juice, Dijon mustard, garlic powder, dried oregano, salt, black pepper, and olive oil if you're using it. Stir everything together until well combined. If you prefer a silky-smooth dressing instead of visible cottage cheese curds, blend the mixture in a blender or food processor for about 20–30 seconds until smooth and creamy. Taste the dressing and adjust the seasoning if you'd like a little more lemon juice, pepper, or herbs.

Place the diced cooked chicken into a large mixing bowl. Add the diced cucumber, halved cherry tomatoes, chopped celery, red onion, and fresh parsley. Spread the ingredients out evenly before adding the dressing so it coats everything more uniformly.

Pour the prepared cottage cheese dressing over the chicken and vegetables. Using a silicone spatula or a large spoon, gently fold the ingredients together until every piece of chicken and every vegetable is lightly coated. Mix slowly and carefully to keep the tomatoes intact and the vegetables crisp. Avoid vigorous stirring, as it can crush the vegetables and make the salad lose its fresh texture.

Taste the finished salad and make any final adjustments. Add an extra pinch of salt or black pepper if needed, squeeze in a little more fresh lemon juice for extra brightness, or sprinkle in additional chopped parsley for a fresher flavor. If you'd like even more Mediterranean flavor, you can also mix in a little extra dried oregano at this stage.

Cover the bowl with plastic wrap or transfer the salad to an airtight container and refrigerate it for 20–30 minutes before serving. Chilling allows the dressing to absorb into the chicken while giving the herbs and seasonings time to blend together, resulting in a creamier and more flavorful salad.

Serve the salad chilled as a complete meal on its own or over a bed of mixed greens for extra freshness. It also makes a delicious filling for lettuce wraps, whole-grain or high-protein tortillas, pita pockets, or sandwiches. Before serving, garnish with a little extra chopped parsley, freshly cracked black pepper, and any optional toppings such as crumbled feta cheese, sliced avocado, pumpkin seeds, sunflower seeds, or a light drizzle of extra virgin olive oil for even more flavor and texture.