Cook pasta per packet directions. Save 1 cup of pasts water, then drain pasta and return to pot.
Heat oil in a large pan on medium heat. Sauté garlic until fragrant.
Add in chicken, season with chilli flakes, salt, and pepper, and stir. Add in the wine and simmer until nearly evaporated.
Add in chicken broth then broccoli and toss and combine. Bring to a simmer. Fold in lemon zest, Parmesan, and herbs. Remove from heat and add in butter, stirring and tossing until fully melted. Add in the Fettuccine, adding in some pasts water if the pasta seems to be dry. Top with additional Parmesan.