Heat a medium saucepan over medium-high heat and pour in the oil. Toss in the sausage, stirring until it begins to brown (approx. 3 mins). Add the onion and garlic, sautéing until they are lightly browned (approx. 3 minutes more). Pour in the tomatoes, add the herb sprigs and one cup water, stirring until everything is boiling. Reduce the heat and allow everything to simmer, with a lid on, for 10 minutes.
Discard the herb sprigs and add 2 teaspoons of salt. Spice it up with some pepper, then enjoy it right away or store it in the fridge for up to 3 days or freeze for a maximum of 2 months.
Now, it's time to cook the pasta. Preheat the oven to 400 degrees F. Grease an 11 by 13-inch baking dish with olive oil.
Bring a large pot of salted water to a boil and cook the pasta until it's al dente yet still slightly firm. Drain off the water afterwards.
Combine the cooked pasta, quick tomato sauce, cubed mozzarella, half of the Parmesan, black pepper and crushed red pepper in a large bowl and give it a good toss. Move the mixture to your prepped baking pan. Place the mozzarella slices on top of the pasta and add a sprinkle of the remaining Parmesan. Bake until it's lightly browned and hot, about half an hour. Serve while it's still steaming!