Set the Instant Pot or electric pressure cooker to saute on high. Heat the oil in the pot.
Slice the smoked sausage into 1/4 inch rounds and place in the pot, cooking until browned on each. Remove sausage from the pot and set aside.
Add the macaroni, water, mustard powder, salt, and pepper to the pot.
Place the lid on the pressure cooker and set to sealing.
Cook on manual pressure for 3 minutes.
Quick release the pressure and remove the lid. Do not drain the liquid.
Turn the pressure cooker to saute and stir in the evaporate milk and hot sauce.
Stir in the cheese, one handful at a time, until it's all melted and combined.
Stir the sausage into the macaroni and cheese, taste and season with additional salt or pepper, if needed. Top with parsley, and serve.