Cut the romaine lettuce into bite-sized pieces.
Boil the chicken breast, let it cool, then shred it into bite-sized pieces.
Cut the cherry tomatoes in half.
Add lettuce, chicken breast, cherry tomatoes, and boiled eggs to a salad bowl.
Mix Greek yogurt, lemon juice, Dijon mustard, and pepper to make the dressing.
Drizzle the dressing over the salad and toss lightly.