Get a large pot of water on the stove to boil and salt it generously. Have a large bowl of ice water handy. Let the Broccoli Rabe (1 bunch) boil in the pot for a minute.
Remove the rabe and plunge it right into the big bowl of ice water to stop the cooking. Blanching it like this helps reduce the bitterness and keeps it pretty and green! Set the bowl aside but leave that newly flavored boiling water boiling.
Heat the Canola Oil (1 dash) in a large cast iron skillet over medium high heat. Brown the Spicy Italian Ground Sausage (1 pound) completely in it while you break it up, which should take about 5 minutes.
Once it is cooked, stir the Butter (6 tablespoon) and All-Purpose Flour (6 tablespoon) in to start a basic roux.
When the flour is completely cooked off after a minute or so, keep stirring while you slowly pour in the Milk (3 cup). Season the sauce with the Salt (1 pinch) and Crushed Red Pepper Flakes (1 pinch). Allow it to bubble and thicken for 10 minutes.
While the sauce cooks, pour the Rigatoni (1 pound) into the pot of boiling water you used to blanch the broccoli rabe. Let it cook and get tender for about 8 minutes.
Drain the broccoli rabe out of the ice water bowl and get it onto a cutting board. Cut it all in half just to make it more manageable to stir in and eat.
Grate the Asiago Cheese (1/2 cup).
When the ten minutes for the sauce is up, stir in the broccoli rabe and grated Asiago cheese and let them meld together for another two minutes. The pasta should also be done by this point.
Drain it and transfer it to a huge pasta serving bowl. Pour the sauce right over it and thoroughly toss it all together. Serve family style immediately with extra grated asiago cheese on top! Enjoy!