2 bunches of beets, washed and sliced as thin as possible
Line a low rimmed cookie sheet or jelly roll pan with aluminum foil. Spray the foil with non stick cooking spray. Put sliced beets in a single layer on the pan (you may need two pans). Preheat the oven to 400 degrees. Drizzle the beets with olive oil and toss the oil and beets together. Roast in the oven until the beets are soft and a little crisp on the edges (the peel will come right off). Sprinkle generously with kosher salt.