Creamy Instant Pot Macaroni and Cheese

INGREDIENTS

1 lb

macaroni pasta, such as shells or cavatappi

4 cups

water

4 tbsp

butter

1 tsp

kosher salt

1 tsp

ground mustard

1/2 tsp

garlic salt (optional)

1 5 ounce can

evaporated milk

4 cups

shredded medium or sharp cheddar cheese

2 cups

soft white cheese such as gouda, Swiss, fontina, or provolone