In a shallow bowl or baking dish, whisk together the flour, 1 tablespoon garlic powder, Italian seasoning, ½ tablespoon kosher salt and ¼ tablespoon pepper to combine. Set aside.
In a separate shallow bowl, whisk the milk with the remaining garlic powder, salt and pepper. Set aside.
In a third shallow bowl, whisk together the bread crumbs and cheese to combine. Set aside.
Dredge 1 chicken breast half in the flour to coat, shaking off the excess. Dredge the chicken in the milk and then the breadcrumb mixture pressing the breadcrumbs into the surface of the chicken to help it stick. Place on a baking sheet lined with parchment. Repeat with the remaining chicken.
Heat 2 tablespoons oil in a large skillet over medium high heat until shimmering.
Add the chicken to the skillet being sure not to crowd the pan. You may need to do it in batches of two chicken breast halves at a time.
Cook the chicken until crispy and golden brown, approximately 4 to 5 minutes. When the chicken releases easily from the pan and is golden, flip it over and continue cooking on the other side until crispy. Repeat with the remaining chicken. Set aside.
Fill a large stock pot with water and bring to a boil. Add the broccoli rabe to the pot and blanch for 1 minute. Drain the broccoli rabe and pat dry with a towel.
Heat 1 tablespoon oil in a skillet and add the broccoli rabe to the pan. Saute the broccoli rabe for 2 to 3 minutes seasoning with salt and pepper, to taste. Set aside.
In a small bowl, stir together the mayonnaise and pesto. Spread the mayonnaise on the cut sides of the bread covering completely.
Layer the provolone cheese on the bottom half of the bread. Top the cheese with the chicken.nArrange the roasted red peppers and broccoli rabe on top of the chicken.nPlace the top half of the bread on the broccoli rabe and slice into individual pieces approximately 3 inches wide. Serve immediately.
Notes
The chicken and broccoli rabe can be made up to 8 hours in advance. To reheat the chicken and make it crispy again, bake in a 350 degree oven for 10 minutes on a baking rack.