Boil a large pot of salted water over high heat. Add spaghetti and cook according to package instructions until al dente, typically 8-10 minutes, then drain.

In a large skillet, heat olive oil over medium heat. Season chicken with paprika, Italian seasoning, salt, and pepper. Cook chicken for 5-7 minutes until golden brown, then let rest and slice.

Melt butter in the same skillet over medium heat. Sauté chopped onion for 3-4 minutes until translucent, then stir in minced garlic and cook for 30 seconds.

Pour in chicken broth and heavy cream; bring to simmer and thicken for about 5 minutes.

Reduce heat to low, add cooked spaghetti and sliced chicken, and toss gently to coat with sauce.

Sprinkle shredded Monterey Jack cheese over the mixture. Cover and let sit for 2-3 minutes to melt cheese.

Garnish with parsley before serving, alongside garlic bread or a side salad.