Combine dry ingredients. Then add olive oil, vinegar, and water. Mix well (i.e. using stand mixer on high for 3 minutes). Divide in half and place on cookie sheet. Using flour (your choice) press the dough into a circle. Brush with olive oil and sprinkle with salt. Bake at 400 °F for 15-20 minutes.
This recipe calls for oregano which makes it kind of like a focaccia, but I have also omitted the oregano and enjoyed the regular bready taste. I've used it as a pizza crust, as pita bread (for dipping in hummus), and as a sandwich bread. It can also be fried and cinnamon-sugar covered for a sweet treat.
Guar gum can be substituted for the xanthan gum.
Corn Substitutions: Corn is a common ingredient in products. Starch, modified food starch, dextrin and maltodextrin can be from corn. Consult with your physician to find out which corn derivatives you need to avoid. Many corn-free options are available in the US. Find out more about corn substitutions.
Gluten: Gluten is a protein found in specific grains (wheat, spelt, kamut, barley, rye). Other grains are naturally gluten-free but may have cross-contact with gluten-containing grains. Look for certified gluten-free products if you need to avoid gluten. Find out more about wheat and gluten substitutions.