Step 1: On medium-high heat, bring a large pot of salted water to a boil.
Step 2: To a large, wide pot, heat the oil over medium heat. Once the oil is hot, add the onion and crushed red pepper to the pot and cook for about 10 minutes until the onion is very tender. Add the sausage and cook until brown, breaking it into small pieces with a wooden spoon. Then, add the garlic and continue to cook for a minute more until aromatic before stirring in the tomato paste.
Step 3: To the pot, add in the tomatoes and pour in the wine or stock. Season with salt and pepper and cook for approximately 10 minutes while stirring occasionally until the tomatoes start to burst, giving off their juices. Gently press the tomatoes using a wooden spoon if they failed to burst on their own. Then, stir in the zucchini, cooking for another 5 minutes.
Step 4: Meanwhile, into the boiling water, cook the rigatoni for about 9 to 10 minutes until al dente. Drain the pasta when done, reserving half a cup of pasta water.
Step 5: Into the pot, immediately toss the pasta, coating it with the sauce. If needed, add the reserved pasta water. Lastly, stir in the basil.
Step 6: Take the pot off the heat and divide the Rigatoni among the serving bowls. Before serving, top each with cheese. Enjoy