I considered calling this 'home-style' blue scalloped potatoes, but really they're just MY HOME style, i.e. the way my mom makes 'em. Possibly New England is too broad perhaps "East Sandwich style Blue Scalloped potatoes" Regardless of the name, I love 'em.
4-5 medium potatoes - get the BLUE ones (N.B. Blue ones are usually a bit smaller so more like 6)
1 yellow onion
2 tbs butter
1/2 cup milk
1/2 cup shredded cheese
1. preheat oven to 350
2. wash the potatoes well (I leave skins on) and slice them into 1/3in slices.
3. cut the onion up into rings
4. butter a 9x9 pan
5. layer potatoes, onion, potatoes, cheese until the pan is full or ingrediants are used up. I split the onion up into individual rings.
6. top with a little extra cheese and pour the milk over the top
7. bake at 350 until the potatoes are cooked and top is cheesy. (you can cover with tin foil to keep it from getting too brown.
P.S. the potatoes get less purple as you bake them, and they taste just like the white ones, but they look cool!