"That Potato Soup"

3 pounds potatoes. 
(Use Russet if you like potatoes that fall apart. Yellow Gold/Yukon if you like firm potatoes)
Boil peeled, cubed potatoes in WELL salted water until tender. (This takes about 15 minutes.) Drain and set aside.

1 stick butter
1 LARGE onion, diced
4 stalks celery, diced.
2 cloves garlic

When tender, add:
1/2 teaspoon ground white pepper
1/2 teaspoon celery seed
1 Quart milk
Cooked potatoes.

Thicken with:
3 Tablespoons cornstarch mixed with 1/2 cup COLD water.
I omit this step sometimes, and simply puree about 1 1/2 cups of the soup in a blender and add back to thicken it.

Adjust salt and pepper to taste.

Cook for about 10 minutes until nicely thickened.