How To make Potato Soup with Onions and Cheddar(Pressure Cooked)

2 tablespoons butter or oil
1 clove garlic

finely minced
4 stalks celery :

thinly sliced
3 scallions

thinly sliced
10 ounces pearl onions :

peeled
2 pounds potatoes

* see note
6 cups beef, chicken, or vegetable stock
1/2 cup finely minced fresh parsley :

divided
1/2 cup milk

optional
1 cup grated sharp Cheddar cheese
salt and white pepper :

to taste
serves 6
*Thin skinned varieties such as Maine, russets, new potatoes are wonderful to u se without peeling. Their delicate skins become very tender and infuse the bro th with a full-bodied flavor. Scrub them, halve, and cut into 1/4" slices
Heat the butter in the cooker. Saute the garlic, celery, and scallions for a m inute or two. Stir in the onions and potatoes, tossing to coat with the butter . Add the stock and 1/4 cup parsley. Lock the lid in place and over high heat bring to high pressure. Adjust heat to maintain high pressure, and cook for 5 minutes. Let the pressure drop naturally or use a quick release method. REmo ve the lid, tilting it away from you to allow any excess steam to escape. Add the remaining parsley and milk (if using). Over low heat, gradually stir in th e grated cheese, simmering until the cheese is melted and the soup is hot. Add salt and pepper to taste before serving.