While you're preparing the chicken, assemble all the raw vegetables for maximum efficiency. Roughly chop the romaine lettuce into bite-sized pieces, halve or slice the tomatoes into 1/2-inch pieces, thinly slice the red onion into half-moons, dice the cucumber, and add everything to a large bowl along with the olives. This mise en place keeps your salad components ready to dress right before serving, which helps maintain the crispness of the lettuce.

Heat the olive oil in a large skillet over medium-high heat until it shimmers. While the oil heats, pat the cubed chicken breasts dry with paper towels and season generously with oregano, salt, and pepper on all sides. Once the oil is hot, add the chicken in a single layer without crowding the pan—work in batches if needed—and let it cook undisturbed for 5-7 minutes until the bottom is golden and caramelized before flipping. I like to season the chicken right before it hits the pan so the spices don't get washed away by any moisture on the surface.

Flip the chicken cubes and cook for another 5-7 minutes on the second side until the internal temperature reaches 165°F when checked with an instant-read thermometer. Remove the skillet from heat and let the cooked chicken rest for 5 minutes on a plate—this allows the juices to redistribute throughout the meat, keeping it tender and moist rather than dry when you add it to the salad.

Pour the Greek dressing over the raw vegetables from Step 1 and toss gently to coat everything evenly. Divide the dressed salad between serving plates or a large platter. I prefer to dress the base salad just before assembly because it keeps the lettuce from getting wilted and soggy.

Arrange the rested chicken cubes from Step 3 on top of the dressed salad. Drizzle or dollop the tzatziki sauce generously over the chicken, then sprinkle the feta crumbles and fresh chopped dill across the top. Serve immediately while the chicken is still warm and the salad is crisp.