One-Pot Italian Shells and Cheese

Set a large, deep skillet or pot over medium heat. Pour the oil into the skillet or pot and let it heat up. Add the onions and garlic to the hot oil. Cook, stirring occasionally, for about 2 minutes, until the onions start to become translucent and the garlic is fragrant. Then, add the sausage to the skillet or pot. Use the back of a wooden spoon to break up the meat as it cooks. Keep cooking until the sausage is cooked through and no longer pink, which should take about 7 minutes. If there's excess fat in the skillet or pot, drain off all but 2 tablespoons of it.

Add the salt, onion powder, dried oregano, black pepper, and red pepper flakes (if using) to the skillet or pot. Stir the ingredients together to combine them. Cook for about 2 minutes, allowing the spices to lightly toast and release their flavors. Next, add the tomato paste to the mixture. Stir it well and cook for 1 minute, or until the paste has totally melted and combined with the meat.

Add the red wine vinegar, beef broth, tomato sauce, and pasta to the skillet or pot. Stir everything together to combine. Bring the mixture to a boil over medium - high heat. Once it's boiling, reduce the heat to a very subtle simmer. Cook the mixture, stirring often, for 13 to 15 minutes, until most of the liquid has been absorbed and the pasta is al dente.

Remove the skillet or pot from the heat. Mix in the ricotta and cheddar cheese. The pasta should be hot enough to melt the cheeses, but if they aren't melting, you can put the skillet or pot back over low heat for a short time. Once the cheeses are fully combined with the pasta, taste the dish and add salt if needed. Garnish the dish with more cheddar cheese and parsley. Serve immediately.