Cook the pasta according to package instructions, drain and set aside.
In a small bowl, combine the italian seasoning, garlic powder, salt, black pepper.
Meanwhile, beat the chicken breast until even in thickness and season with the seasoning mixture on all sides.
In a large deep skillet, heat oil over medium/high heat. Once hot, sear the chicken on both sides until golden and crispy.
Turn the heat down to medium low heat, close the skillet with lid and cook until the chicken is fully cooked. Remove from the skillet, cover to keep warm, and set aside.
In the same skillet, add butter and chopped onion and saute on medium heat until tender and golden.
Add the minced garlic and cook until fragrant. Add the marinara sauce and bring to a light simmer.
Slice the cooked chicken into thin strands or cube into bite-sized pieces. Add the cooked chicken, pasta, and 3/4 cup of the shredded cheese, parmesan cheese into the skillet and toss until combined.
Allow the pasta to cook over low/med heat. Top with the remaining shredded cheese and cover with lid, cook until cheese melts.
Serve and enjoy!