Trim root end and stalks from fennel bulb. Finely chop fennel fronds; set aside. Cut bulb in half lengthwise and trim out core. Cut each half lengthwise into thin slices; set aside.

In a large pot of boiling salted water, cook pasta according to package directions until tender, but firm (al dente). Drain, reserving 1 1/2 cups of the pasta cooking water; return pasta to pot.

Meanwhile, in a skillet, melt butter over medium-high heat; add sliced fennel bulb, pancetta and garlic and saute for about 5 min or until fennel is tender.

Whisk flour into cream and stir into pan; cook, stirring, for about 3 min or until thickened.

Stir in the grated Parmesan cheese.

Add to pasta in pot and gently toss, adding the arugula and enough of the reserved water to moisten.

Season to taste with salt and pepper. Top each serving with shaved Parmesan cheese and fennel fronds.