Gluten-Free Focaccia

To make the dough, place the dry ingredients (except the yeast) into a large mixing bowl. Mix until thoroughly blended., Place the warm water, olive oil, yeast, and about 1 cup of the dry mixture into a small bowl. Stir to combine; a few lumps are OK. Set aside for 30 minutes or so, until the mixture is bubbly and smells yeasty., Add this mixture to the dry ingredients, and beat on medium-high speed for 4 minutes. The mixture will be thick and sticky, but not elastic; it won't feel like regular yeast dough. Note: you must use an electric mixer to make this dough; mixing by hand doesn't do a thorough enough job., Cover the bowl, and let the dough rest/rise for 30 minutes or so., Preheat the oven to 375°F., Use non-stick vegetable oil spray to lightly grease a 9" x 13" pan, or two 9" round pans. Drizzle the 2 tablespoons olive oil atop the spray in the 9" x 13" pan; or use 1 tablespoon of the oil in each of the 9" pans. The spray keeps the bread from sticking, while the olive oil gives the bottom crust great crunch and flavor., Sprinkle the herbs (and pepper, if you're using it) into the pan. Don't add the sea salt yet; that comes later., Scrape the dough from the bowl into the 9" x 13" pan, or divide it between the two round pans., Using your wet fingers, start at the center of the dough and work outwards towards the edges, pressing the dough to fill the bottom of the pan., Let the dough rest, uncovered, for 15 to 30 minutes, until your oven is thoroughly preheated., Bake the focaccia for 20 to 23 minutes, until it's set, and the top springs back when pressed. It won't be brown. You'll also notice it's shrunk away from the sides of the pan, and perhaps deflated a bit; that's OK., Remove the focaccia from the oven, and immediately turn it out of the pan onto a cooling rack. It'll be pale on top, golden brown on the bottom — which is why you put the herbs and pepper in the bottom of the pan, rather than sprinkling them on top of the dough. This bread is served bottom-side up, to showcase its golden bottom crust., Sprinkle the focaccia with coarse salt, if you're going to enjoy it immediately. If you're going to reheat and serve it later, or serve it at room temperature, don't apply the salt until just prior to reheating/serving., Cut the focaccia into squares or wedges, and serve. Store any leftovers, well wrapped, at room temperature for a day; freeze for longer storage (up to a month).