Place chicken on a greased grill or grill pan and cook for about 3-4 minutes on each side, or until the chicken is cooked through.
Leave the breast chicken to cool down, slice it and set aside.
FOR THE SALAD
In a large salad bowl, add first the lettuce, and then top it with cucumber, red onions and avocado.
In a mason jar, pour the freshly squeezed lemon juice and olive oil. Add salt and pepper and red crushed pepper. Whisk everything together. Continue to whisk while streaming in the olive oil. Taste to check the seasoning and pour over the salad.