Heat grill to 400F.
Marinate chicken breast with Balsamic Vinegar.For maximum flavor, this can be done for 30 minutes to 4 hours in the refrigerator.
Add chicken to the grill. Grill until white begins to form around the edge of the chicken. Flip the chicken and cook until the internal temperature reaches 165F.
Remove from the heat and allow meat to rest for10 minutes.
Wash romaine lettuce with cool water and chop.
Wash the watermelon and slice into bite-sized chunks.
Arrange the salad on the plate. Slice the chicken into strips. Top with chopped fresh dill, parsley, walnuts and marinated red onions. Enjoy!