Cut the chicken breast into bite-sized pieces and season with salt and pepper.
Heat olive oil in a pan and grill the chicken breast until golden brown.
Wash romaine lettuce and baby greens thoroughly, remove excess water, and place them in a bowl.
Cut the avocado in half, remove the pit, and slice it.
Peel the boiled egg and slice it.
Place the chicken breast, avocado, and egg on top of the greens.
Drizzle balsamic dressing evenly to finish.