1. Heat oven to 350 degrees F.
2. In a clean, large bowl, beat egg whites on medium-high speed to stiff peaks.
3. In a small bowl, whisk together the cake meal, potato starch and salt.
4. In a second large bowl, beat sugar and egg yolks, until lemony in color, about 5 minutes. Beat in zest.
5. Beat in the cake meal mixture in two additions, alternating with the orange juice. Gently fold in beaten egg whites.
6. 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.
7. Remove from oven; immediately invert onto a baking sheet and allow to cool completely.
8. 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.