Add macaroni noodles, water, butter, dry mustard, onion powder, seasoned salt, and pepper to the Instant Pot.
Seal the lid and select manual pressure high. Set the timer for 6 minutes. Manually release pressure once completed.
Do not drain the water in the bottom. Stir in cream cheese to melt. Add ¼ cup milk slowly until blended.
Stir in cheddar and parmesan. Add the remaining ½ cup milk, mixing a little at a time, until desired consistency is reached. You may not need all of the milk.
Notes
Prep remaining ingredients (shred cheese, etc.) while pasta cooks.
Refrigerate mac n cheese for 3-5 days in air tight, individual or meal sized portions. Freeze larger portions in an air tight container for up to 3 months.
Thaw mac and cheese in the refrigerator, then reheat covered in a 350°F oven for 20-30 minutes or until heated through. For individual portions, simply microwave at 15 second intervals, stirring in between, until heated.
Nutrition information does not include optional ingredients or garnish and is an estimate. It may change based on actual ingredients and cooking methods used.