Bring a large pot of salted water to a rolling boil. Add spaghetti or fettuccine and cook until al dente, about 8-10 minutes. Reserve 1 cup of pasta water.

In a large skillet, heat olive oil over medium-high heat. Season chicken with salt and pepper. Sear chicken for 6-7 minutes each side until cooked through. Remove and let rest.

In the same skillet, cook bacon over medium heat until crispy, about 5-7 minutes. Add minced garlic and sauté for about 30 seconds until fragrant.

Lower heat to medium-low, pour in heavy cream, and whisk with bacon fat until combined. Gradually add Parmesan, whisking until smooth.

Add drained pasta and sliced chicken back to the skillet. Toss gently, adding reserved pasta water until desired consistency is reached.

Plate the dish, garnish with parsley and extra Parmesan. Serve hot.