Slice up all the vegetables. Use a mandoline to ensure an even slice each time. Make sure all of veggies are cut into half moons.
Cut open slits about 1/2 inch apart across the center of the chicken. Do not cut through to the other end or across the entire piece. Make sure the pocket is large enough to hold in the veggies.
Drizzle olive oil on the chicken breast and begin stuffing. When stuffing, interchange the veggies or stuffing selection. Season with entire breast with Dad's All Purpose rub.
Preheat the grill to 350 degrees and set for indirect heat. Place the hasselback breast directly on the grates with the stuffing facing up.
When almost cooked, sprinkle the top with shredded mozzarella and allow it to melt over the chicken breast.
Leave them on the grill until the internal temperature reaches 160 degrees.
Let the chicken rest for 10 minutes before serving.
Notes
Use veggies you already have in the fridge or substitute my list with ones you like most.Make large slits on the chicken to allow more filling across the breast.