Start pasta, following directions on the box. Once done, toss with olive oil and set aside, covered to keep warm.

In a dutch oven or large pot, melt butter. Add onion, garlic, celery, rosemary, salt and pepper and saute until soft, for about 5 minutes,

Add wine and let heat for about 1-2 minutes. Add the mussels to the hot wine, cover and steam for 5 minutes, until the mussels open up. Transfer mussels from pot to a separate bowl, with a slotted spoon, tossing any that didn't open into the garbage. Set bowl of mussels aside, keeping warm.

Add cream and Parmesan cheese/flour mix to the remaining wine broth in the pot and whisk vigorously over medium heat until sauce thickens.

Set up bowls with cooked pasta, steamed mussels and pour sauce generously over pasta and mussels.

Serve with steamed broccoli!