Step 1: Sauté the Aromatics - Turn your Instant Pot to the sauté function. Melt the butter and add the diced onion and minced garlic. Sauté for 3-4 minutes until translucent.
Step 2: Add Pasta and Broth - Add the uncooked pasta, vegetable stock, Dijon mustard, nutmeg, salt, and black pepper. Stir to combine.
Step 3: Pressure Cook - Close the lid, set the valve to sealing, and cook on high for 5 minutes. Allow for natural pressure release for 5 minutes, then quick release any remaining steam.
Step 4: Stir in the Cream and Cheeses - Remove the lid and stir in the heavy cream and cheeses until melted and creamy.
Step 5: Garnish and Serve - Sprinkle chopped parsley over the top and serve hot.
Notes
For extra flavor, add smoked paprika or cayenne pepper. You can also experiment with different cheese combinations.