Cook the spaghetti according to package instructions until al dente. Drain and set aside.

Heat olive oil in a large skillet over medium heat. Season the chicken pieces with paprika, Italian seasoning, salt, and pepper. Add to the skillet and cook for 5 to 7 minutes until golden brown and fully cooked. Remove the chicken from the skillet and set aside.

In the same skillet, melt the butter over medium heat. Add the chopped onion and cook for 3 to 4 minutes until softened. Stir in the minced garlic and cook for another 30 seconds until fragrant.

Pour in the chicken broth and heavy cream. Stir well and bring to a gentle simmer. Reduce heat to low and let the sauce thicken slightly for about 5 minutes.

Add the cooked spaghetti and the cooked chicken back into the skillet. Toss gently to combine until the pasta is fully coated with the sauce.

Sprinkle the shredded Monterey Jack cheese evenly over the top. Cover the skillet and let it sit for 2 to 3 minutes until the cheese is melted.

Remove from heat, garnish with fresh parsley, and serve warm.