for the pasta: Boil pasta in salted water per package directions, until al dente. Drain pasta and transfer to a large bowl.

for the peppers and onions: In a large skillet (I like to use this cast iron skillet) over medium-high heat, add the butter. Once butter has melted, add onion, red and green bell peppers, salt, and black pepper. Sauté, stirring occasionally, until veggies become softened and caramelized. Remove skillet from heat and stir in red wine vinegar. Transfer veggies to the bowl with the pasta.

for the chicken: Return same skillet to burner over medium to medium-high heat and add olive oil. Sprinkle chicken with Italian seasoning, kosher salt, and black pepper. Add chicken to skillet and sauté for about 8 minutes, or until no longer pink inside. Transfer chicken to the bowl with pasta and veggies.

for the provolone sauce: Return same skillet to burner over medium heat and add the butter. Once melted, sprinkle flour over the butter and whisk to combine (a flat whisk works awesome here!). Continue to lightly whisk for 1 minute. Gradually add the milk, whisking vigorously to combine and break up any clumps. Let cook for about 5 minutes, whisking every now and then, until mixture has thickened a bit. Add shredded provolone, kosher salt, and black pepper, stirring to combine. Let cook for a minute or two, and then pour sauce into the bowl with the pasta, veggies, and chicken. Fold to combine.

to assemble: Preheat oven to 400°F. Lightly spray interior of a 13" x 9" or similarly sized baking dish with non-stick cooking spray. Transfer chicken cheesesteak mixture to prepared baking dish. Top with provolone slices and place dish in oven. Bake for about 25 minutes, or until everything is hot and bubbling, and the cheese is a bit blistered. Place under broiler to blister a bit more, if desired. Remove from oven and let rest for 5 minutes. Garnish with fresh parsley and serve immediately.