Add the chopped lettuce to a large serving bowl or divide it between two individual salad bowls.
Arrange the sliced Greek marinated chicken breast over the lettuce.
Add the tomato salad, cucumber slices, Kalamata olives, and feta cheese.
Prepare the dressing by combining olive oil, red wine vinegar, garlic, oregano, sugar, salt, and black pepper in a small jar with a lid.
Seal the jar tightly and shake vigorously until the dressing is fully blended and emulsified.
Taste and adjust seasoning with additional salt, pepper, or sugar if desired.
Drizzle the dressing over the salad.
Toss gently to combine and serve immediately.
This Greek Chicken Salad Recipe is best enjoyed fresh while the vegetables are crisp and the dressing is vibrant.