12 eggs, separated
1 whole lemon (with rind)
1 cup matzoh meal
1/2 cup potato starch
1 cup sugar
1.2 cup orange juice
1/2 cup chopped walnuts
Pinch of salt

Beat egg whites on highest speed with a pinch of salt.

Gradually add sugar, beating until stiff peaks form. Sift together matzoh meal and potato starch. Grate the lemon rind. Mix orange juice in the food processor. Add the egg yolks. Blend again until foamy. Add sifted matzoh meal and potato starch to food processor. Blend again.

Carefully fold the mixture from the food processor into the beaten egg whites. Pour into a high-sided ungreased tube pan and sprinkle with chopped walnuts.

Bake for 1 hour at 350°F.

Remove from oven and invert to cool.