Clean the broccoli rabe and cut about 1" off the bottom of the stalks and discard. Cut the stalks in half.
To blanch the broccoli rabe place in the boiling water for about 2 minutes. Plunge the broccoli rabe into a large bowl filled with ice water. This will stop the cooking and set the color. Remove with a slotted spoon and place on paper towels to dry.
Preheat a large saute pan on medium heat and add the olive oil to heat. Add the turkey sausage, garlic and crushed red pepper flakes and saute, stirring occasionally, until the sausage is done. This should take about 10 to 15 minutes.
Add the broccoli rabe, cherry tomatoes, and balsamic vinegar and stir to combine. Cook another 2 to 3 minutes.