In a food processor or high powered blender pulse the oats, until fine like flour.
In a food processor combine the oat flour, brown rice flour and butter, pulse until crumbly.
Add the water 1 Tbs at a time until the dough comes together and starts to clean the side of the bowl.
Roll the dough into a ball and flatten into a round, cover in plastic wrap and place in the refrigerator.
Preheat your oven to 325º F.
In a 10" cast iron skillet heat the olive oil over medium heat and sauté the Swiss chard, Portobello mushrooms, shredded carrots and onion until tender, about 5 minutes.
Transfer the filling to a bowl and set aside.
Wipe the residue from the skillet and roll the dough out to 1/4" thick.
Center the dough into the skillet and add the filling to the center of the crust and sprinkle the shredded cheese on top.
Fold the edges in, overlapping as you go.
Bake for 25-30 minutes, until the crust is golden and the cheese is melted.
Let cool 10 minutes, slice and serve warm.
Coursesbreakfast, brunch, vegetable, galette
Recipe by It Bakes Me Happy at http://itbakesmehappy.com/2015/05/gluten-free-swiss-chard-mushroom-galette.html