Bring a large pot of water up to a rolling boil.

While the water heats, start cooking the sausage. Break it up in a large skillet over medium-high heat. You can use a wooden spoon or spatula, but I find a potato masher works best. 

Add the garlic cloves and chili flakes (if using), then cook until the sausage is nicely browned. 

When the water is boiling, season generously with salt then add the broccoli rabe. Cook until al dente, about 2 minutes, then use a spider or handheld strainer to remove it from the water.

Drain the broccoli rabe well, then add it to the pan with the sausage and stir to combine. Let simmer over very low heat. 

Add the chick pea pasta to the water (make sure it's still at a rolling boil), stir, then cook according to package directions until al dente. 

Reserve a cup or two of pasta cooking water, then drain and rinse under cold water. 

Add the pasta to the pan with the sausage and broccoli rabe, turn up the heat and toss until well combined. Add pasta water a few splashes at a time along with the parmesan cheese, then continue tossing until it creates a nicely thickened sauce. 

Spoon pasta into bowls, then drizzle each with a bit of olive oil and sprinkle with parsley. Serve hot with more parmesan cheese for sprinkling.