In a large deep skillet or pot, combine the dried fettuccine noodles, fresh broccoli florets, minced garlic, and vegetable broth.
Bring the mixture to a boil over medium-high heat, stirring occasionally to prevent the noodles from sticking.
Once boiling, reduce the heat to medium and simmer for about 8 to 10 minutes, stirring frequently, until the noodles are al dente and the broccoli is tender.
Stir in the whole milk, unsalted butter, salt, black pepper, and crushed red pepper flakes.
Add the freshly grated Parmesan cheese and stir continuously until the cheese is fully melted and the sauce becomes creamy, about 2 to 3 minutes.
Taste and adjust seasoning with additional salt or pepper if needed.
Remove from heat and let the noodles sit for 2 minutes to thicken the sauce before serving.