Instant Pot Mac and Cheese

INGREDIENTS

1 tbsp

unsalted butter

1/2 cup

grated onion ((about 1 medium onion))

2 cloves

garlic, (minced)

1 tsp

salt

1/2 tsp

ground pepper

1/2 tsp

ground mustard

-oz box small shell pasta, (uncooked)

4 cups

water

1 1/2 cups

milk ((I used 2%))

1 cup

shredded pepper jack cheese

1 cup

shredded mozzarella cheese

1/2 cup

shredded smoked gouda cheese

1/2 cup

shredded sharp cheddar cheese