Preheat the oven to 400 degrees F.

To make a starchy pasta water without cooking pasta, combine 1 cup of water with ½ teaspoon of cornstarch and ¼ teaspoon salt. Bring it to a boil in a saucepan, then turn off the heat! Set it aside until ready to use.

Heat the butter in a 10 to 12-inch oven-safe saucepan or skillet over medium heat. Once melted, stir in the shallots and garlic with a big pinch of salt and pepper. Cook, stirring often, until the onions soften. Add in the tomato paste and stir, cooking for 5 minutes. The color will darken - this is where the flavor is!

Stream in the vodka and stir, scraping the brown bits and flavor from the bottom. Stir in ½ to 1 cup of the reserved (or makeshift) pasta water. Stir in the heavy cream and parmesan, stirring until the cheese melts. Taste and season the sauce with more salt and pepper if needed.

Stir in the uncooked tortellini. Sprinkle with the mozzarella cheese. Sprinkle with parmesan.

Bake for 15 to 20 minutes, until the cheese is melty and bubbly. Serve, topped with parmesan and fresh basil.