In a medium mixing bowl, whisk together the egg whites, sugar, and potato starch.

Heat the margarine in the microwave for about 45 seconds or until melted. Add it to the egg mixture and whisk together.

Add the orange zest and whisk until it is mixed in. Add the almonds and mix gently with a silicone spatula, trying not to break the nuts. Cover the bowl with plastic wrap and refrigerate for a minimum of two hours or overnight.

When you’re ready to bake the cookies, preheat the oven to 400 degrees Fahrenheit. Use a non-stick baking sheet or grease a regular cookie sheet. Drop teaspoons of the batter onto the sheet, three to four inches apart. Do not prepare more than 10 cookies at a time on one cookie sheet. With a fork dipped in water, flatten the batter of each cookie, spreading it gently and separating the nut slices, until the circles are about three inches round. (This takes time; the more patient you are, the thinner and crispier the cookies will be. Once a cookie sheet is in the oven, repeat on a second sheet.)

Bake for seven to eight minutes, or until the edges are brown and the center is golden-brown. Remove the cookies from the oven and allow to sit for about 15 seconds. Use a flat blade metal spatula to lift the cookies and place them on a curved mold or around a rolling pin so that they bend on their undersides and the topsides have the almonds. Let the cookies cool.

Store them covered with plastic or in an airtight container at room temperature for five days or freeze for up to three months.