In a small bowl combine the caraway seeds and the vodka, set aside. Sauté the olive oil and onions in the Instant Pot on the highest SAUTE setting for a minute or two. Stir in the garlic and mushrooms, and cook for a few minutes more, until everything softens up a bit. Stir in the tomato paste, and then the flour, and cook, stirring gently, but constantly for another few minutes, to toast the flour a bit. Add the mustard, salt, and pepper, broth, and pasta. Give one last stir to distribute the pasta evenly, and press CANCEL to stop the SAUTE.
