In a large bowl, dissolve yeast in warm water (about 110°). Mix in salt, olive oil and 2 cups of gluten-free flour with a wooden spoon. Use hands to knead last ½ cup gluten-free flour into mixture and form a ball of dough. Lightly coat ball with shortening. Return to bowl and cover with a sheet of parchment paper or a clean kitchen towel. Let rise until dough has doubled in size, about 45 to 60 minutes.
Preheat oven to 400°. Prepare a baking sheet with a layer of olive oil. Punch down dough (it gets sticky so put a little olive oil on your hands for this step) and remove from bowl. If making 2 small flatbread, divide dough into 2 pieces. Put 1 piece on baking sheet and flatten with tips of fingers. Repeat with second piece.
Drizzle or rub a little olive oil on top of dough.
Place in preheated oven and bake for 12 to 15 minutes. Remove from oven and add toppings. Return to oven and bake until crust is golden.