**Cook the pasta** Bring a large pot of salted water to a boil. Add the pasta and cook according to package directions until al dente. Reserve about 1/2 cup of pasta water before draining.
**Cook the broccoli** If using fresh broccoli, add it to the pasta pot during the last 2–3 minutes of pasta cooking. Alternatively, sauté the florets in a skillet with a little oil until crisp-tender. If using frozen broccoli, thaw and drain thoroughly before adding to the dish.
**Make the sauce** In a large skillet over medium heat, warm the Boursin cheese with the milk or cream. Stir gently until the cheese melts and forms a creamy sauce. If the sauce seems too thick, add some reserved pasta water or more milk.
**Combine** Add the cooked pasta and broccoli to the skillet. Toss well to coat everything in the Boursin sauce. Season with salt and black pepper, adjusting to taste.
**Serve** Garnish with extra Parmesan, fresh herbs, or a sprinkle of red pepper flakes if desired. Serve immediately.