Preheat the oven to 375°F.
Mix all of the ingredients for the sauce, season with salt and pepper. Taste and adjust any ingredients as needed. Refrigerate until ready to use (increase amounts for more sauce if desired).
Place wooden skewers on each side of the potato slice. Make horizontal slices across the potato (the wooden skewers will prevent the knife from slicing all the way through the potato).
Flip the potato slice over, keep positioned between the wooden skewers, and make diagonal slices on the other side (potato will spread apart like an accordion if done properly).
Season both sides with oil, paprika, garlic powder, salt and pepper. Place on a foil-lined baking sheet and cook for about 30 minutes, flipping over halfway through to cook both sides, until golden brown and tender.
Preheat a grill over medium heat (if desired) and cook the sausage on both sides until an internal temperature of 155°F is reached using a thermometer (alternatively, cook the sausage on the same pan as the potatoes in the oven, if desired).
In a saucepan over low heat, add the butter and garlic. Slowly melt the butter. Once melted remove from the heat and stir in the parsley. Then spread on one half of the rolls. Spread the cheese on the other half.
Toast the rolls till golden brown and cheese melted.
Place the potatoes on the roll, top with sliced sausage and bread. Cut in half and serve with sauce on the side for dipping the mozzarella sticks and sandwich if desired.