Combine yeast, sugar, and water in a bowl. Leave for 10 minutes.
Whisk together the gluten-free flour, cornmeal, salt, and xanthan gum in a bowl.
Add the yeast mixture and olive oil into the dry ingredients. Stir until dough comes together.
Knead the dough.
Set the dough in a lightly oiled bowl and leave to rise for an hour.
Flatten the dough with a rolling pin.
Press the dough onto a 9-inch pie pan.
Bake the crust for 5 minutes at 425F.
Spread the cheese on the bottom of the crust.
Top the cheese with chopped salami.
Finish the layers with crushed tomatoes.
Bake at 350F for 15-20 minutes.