Start the Instant Pot on SAUTE mode and add butter and oil. Once oil is heated, add mushrooms and garlic. Sprinkle pinch of salt and let them cook until mushrooms start to release the water. (3-5 minutes)
Once mushrooms have browned, cancel SAUTE. Remove cooked mushrooms and set them aside.
Add water and deglaze the pot by scrapping the bits stuck at the bottom. Make sure nothing is stuck at the base. Add uncooked pasta. and equal amount of water to cover the pasta.
Add the wine, Italian seasoning and Dijon mustard to the pan. Stir until it all mixes well. Close the lid. Valve at SEALING.
Check the cooking time mentioned on the pasta box. Now press MANUAL or PRESSURE COOK and choose half of cooking time suggested on the box. (usually 4-5 minutes)
Once Instant pot finishes cooking and goes to KEEP WARM timer, wait for 5 minutes and then release the leftover pressure by moving the valve from SEALING to VENTING. After the silver pin drops, open the lid.
Stir in sautéed mushrooms, evaporated milk and nutmeg. Add salt and pepper. Gently mix everything well together. Garnish with fresh chopped herbs, crushed red chili flakes and black pepper and parmesan and serve. Bon Appetite