Boil a large pot of heavily salted water and cook the fettuccine according to package directions until al dente.
Reserve one cup of pasta water before draining the noodles to adjust sauce thickness later.
Season chicken strips generously with salt and pepper on all sides.
Heat two tablespoons of butter in a large skillet over medium-high heat.
Sear the chicken in batches until golden brown and cooked through, then remove from the pan.
Reduce heat to medium and add the remaining butter to the same skillet.
Sauté the minced garlic for one minute until fragrant.
Pour in the heavy cream and bring to a gentle simmer.
Whisk in the freshly grated parmesan cheese until fully melted and smooth.
Return the cooked chicken to the skillet, toss in the pasta, and combine until coated.
Adjust consistency with reserved pasta water if needed, garnish with fresh parsley, and serve immediately.