In an unheated skillet that will be large enough to hold the pasta, combine the
oil, onion, garlic, red pepper, bay leaf and salt, and toss to coat with the oil.
Place over moderate heat, cooking just until the garlic turns golden but not brown,
2 to 3 minutes.Add the fennel, stirring to combine. Cover and sweat over moderate
heat for 10 minutes, stirring every few minutes.
Add the tomatoes and orange zest. Stir to blend and simmer, uncovered, until
the sauce begins to thicken, about 15 minutes.
Taste for seasoning. Remove and discard the bay leaf.
Cook the pasta according to package directions until tender but still firm to
the bite. Drain and add to the skillet with the fennel sauce and toss to coat. Cover,
turn the heat to low and let rest 1 to 2 minutes.
Stir, taste for seasoning and add the parsley.
Transfer to warmed shallow soup bowls and serve immediately.