Heat the olive oil in a large skillet over medium-high heat until shimmering (approx. 2 to 5 minutes).

Add the chicken, onion, salt, garlic powder, and pepper, and cook together (breaking up and chopping the chicken finely with the side of your spatula) until the onions are soft and translucent and the chicken is no longer pink (approx. 3 to 8 minutes).

Place approximately 6 slices of cheese on top of the chicken mixture and allow to soften and melt (approx. 2 to 5 minutes).

Add the half and half, and stir the chicken cheesesteak filling together, continuing to cook, until a thick sauce forms (approx. 3 to 5 minutes).

Line each of the steak rolls with 2 more slices of cheese, and scoop the filling on top.

If the heat of the filling does not melt the cheese enough, wrap the sandwiches in foil and warm them in a 350-degree F oven until fully melted (approx. 10 to 15 minutes).