Source: Martha Stewart - Everyday Food, November 2010
adapted by http://theresalwaysthyme.blogspot.com
2 medium-sized Russet Potatoes, very thinly sliced
6 tablespoons heavy cream (I used 1% milk)
coarse salt and freshly ground pepper
Preheat oven to 400°.
Lightly coat 6 standard muffin cups with unsalted butter. Place two slices of potato in each cup and season with salt and pepper. Continue to add potato slices, seasoning after a few slices, until the cups are filled. Pour 1 tablespoon heavy cream over each cup. Bake until potatoes are golden brown ad tender when pierced with a knife, about 30-35 minutes. Run a knife around each gratin. Place a baking sheet on top of the pan and invert to release the gratins. Flip right side up and serve.