Heat oven to 350 degrees F.
In a clean, large bowl, beat egg whites on medium-high speed to stiff peaks.
In a small bowl, whisk together the cake meal, potato starch and salt.
In a second large bowl, beat sugar and egg yolks, until lemony in color, about 5 minutes. Beat in zest.
Beat in the cake meal mixture in two additions, alternating with the orange juice. Gently fold in beaten egg whites.
Spoon into an ungreased, 10-inch angel food cake/tube pan with feet. Bake at 350 degrees F for 1 hour or until toothpick inserted in cake comes out dry.
Remove from oven; immediately invert onto a baking sheet and allow to cool completely.
Turn over pan and run a small knife or small spatula around edge of pan, and center tube. Remove cake from pan. Serve with strawberries, if desired.
