Season the chicken breast with salt and pepper on both sides.
Cook the chicken: fry in a lightly oiled pan over medium heat, grill, or bake at 200°C (400°F) until fully cooked (about 12–20 minutes depending on method).
Allow the chicken to rest until cool enough to handle, then cut into bite-sized cubes.
Place the cleaned, roughly chopped celery into a blender or food processor and pulse until finely chopped but not puréed.
In a mixing bowl combine the chopped celery, mayonnaise, curry powder, and the finely chopped basil; season to taste with salt and pepper and stir until evenly mixed.
Toss the chicken cubes in the curry-celery sauce until coated.
Serve the dressed chicken on a bed of salad mix.
Notes
Adjust curry powder to taste for milder or stronger flavor.