In a 12-inch skillet, melt the butter over medium-low heat. Add the shallots and cook, stirring occasionally, until translucent, 3 to 5 minutes. Add the garlic, oregano, and pepper flakes and cook until the garlic is fragrant, about 1 minute. Add the tomato paste and cook, stirring occasionally, until the paste has darkened in color and turned the butter bright orange, 2 to 3 minutes.

Increase the heat to medium and add ⅓ cup of the vodka. Cook until the liquid has almost completely evaporated. Add the tomatoes, 1 teaspoon salt, and a few grinds of black pepper. Bring to a boil, then reduce the heat and simmer, stirring occasionally, for 10 to 12 minutes, until the sauce is thickened.

While the sauce is cooking, pat the shrimp dry with a paper towel and sprinkle them with salt and pepper.

Add the shrimp to the skillet and cook until they are just beginning to become opaque, about 3 minutes. Stir in the heavy cream and simmer until the shrimp are just cooked through, about 1 more minute.

Off the heat, stir in the remaining 1 tablespoon vodka and the Parmesan. Taste for seasonings, and serve hot sprinkled with the parsley, with crusty bread on the side.