Simmer or steam the broccoli raab for about 3 minutes, until it is bright green and beginning to become tender. Drain and plunge it into icewater for a few moments.
Cook the sausage over medium heat in a large, deep skillet, pricking it with a fork or thin-bladed knife a few times, and turning from time to time until it is nicely browned.
Remove the sausage from the skillet and cut it into bite sized pieces. Return it to the skillet, over medium heat; cook, turning occasionally, until all sides of the sausage are nicely browned, about 5 more minutes.
Squeeze the excess liquid from the broccoli raab and chop it coarsely. Add it to the skillet along with the garlic and cook, stirring occasionally, for 3 or 4 minutes. Check for salt and sprinkle liberally with pepper. Serve over pasta immediately.