In a large bowl whisk together yeast, water and sugar. Let sit 5 minutes, or until foamy.
Add in olive oil, flour, cornstarch, xanthan gum and salt.
Stir with wooden spoon until a small ball forms. Cover and set in a warm area for 30 minutes.
Preheat grill to medium-high heat (about 400°F).
Divide dough into 4 equal pieces. Using two sheets of parchment paper place one piece of dough between them and roll out to thin round disk, about 1/2-inch thick. Repeat with remaining dough pieces.
Brush both sides with olive oil and place on grill. Cook about 4 minutes on each side.
Remove from grill and sprinkle with 1/4 tsp Italian seasoning. Top with desired toppings and place back on grill for about 3 minutes.