This saute is delicious as a side dish or tossed with pasta as a main.
Heat olive oil in a large skillet over medium heat; add garlic, anchovy fillets (if using), and crushed red pepper. Cook, stirring, until anchovy breaks down and garlic is just golden, 30 to 60 seconds.
Add chicken sausage; increase heat to medium-high. Cook, stirring occasionally, until opaque, 3 to 5 minutes.
Add raisins and as much broccoli rabe to skillet as will fit; season with salt and pepper. Cook, tossing and adding remaining broccoli rabe as there is room; cook until broccoli rabe is tender, 6 to 10 minutes (less if it has been blanched).
Season with salt, pepper, and lemon juice to taste. Serve.
You can reduce the broccoli rabe bite by blanching and shocking it (giving it a brief dunk in salted boiling water followed by a dip in ice water).