Stir together 1/2 cup of the rice flour, the yeast, sugar and 1/2 cup of the warm water in a 2-cup glass measure. Let rest in a warm place until doubled in volume, about 10 minutes. Line a large baking sheet with parchment paper and draw two 8-inch circles on it (use a cake pan as a guide).

Beat egg whites lightly; add olive oil, chopped olives and 2 teaspoons of the rosemary. Set aside.

Combine garlic and egg yolk. Set aside.

Combine remaining 1 cup rice flour, the corn flour, cornstarch, xanthan gum and salt in a bowl. Add remaining ¾ cup warm water to egg white-olive mixture and stir into flour. Stir in yeast mixture and beat until smooth.

Using a rubber spatula, spread soft dough into 8-inch circles marked on the parchment paper, heaping it up slightly in the middle. Cover loaves with lightly greased plastic wrap and let rise until doubled in bulk, about 1 hour.

Preheat oven to 425°F.

Discard garlic and brush egg glaze over loaves. Sprinkle tops with remaining 2 teaspoons of rosemary. Using a razor blade, slash the tops of loaves into a large diamond grid pattern. (Use an up and down cutting motion rather than dragging the blade through the soft dough.)

Bake for 20 minutes, until well browned. Makes two 8-inch loaves (12 slices each).