Preheat a panini grill or george foreman style grill. (or preheat an oven to 350 degees)
Preheat a grill or grill pan on medium heat, season both sides of the chicken with salt and pepper and cook about 2 - 4 minutes on each side until it is no longer pink inside and reaches an internal temperature of 160 degrees. (cook time depends on how thick the breast is.) Once cooked thinly slice the chicken.
In a blender or food processor pulse the mayo, basil, and garlic until smooth.
Spread the mayo on the bread and layer with arugula, tomato seasoned with salt and pepper, chicken, onion, and fresh mozzarella.
Lightly grease the panini style grill with nonstick spray and press the sandwich down, cook until the bread is crispy and the cheese is melted. (Alternatively lightly grease a nonstick pan on low medium heat with nonstick spray and cook both sides of the sandwich until golden brown and melted while covering with a lid) Cut in half and serve with pickles and chips.