While potatoes are boiling, heat butter in a skillet over medium-low heat, stirring occasionally, making sure butter doesn't burn. Cook until butter is fragrant and completely brown in color. Set aside.
Drain potatoes and pat dry with paper towels. Place in a single layer on a large rimmed baking sheet. Pour brown butter evenly over potatoes and let them "marinate" for about 10 minutes, flipping once. Sprinkle generously with salt and pepper.
As you can see, I sliced my spuds just a little too thinly, so don't skimp on the slices. They should be a real half-inch thick, and will in turn absorb more butter and keep from burning in the oven. Enjoy these beauties!