Warm the water and add yeast and sugar to it. Mix well and let it get frothy. 8-10 minutes.
In a bowl, whisk all the dry ingredients (flours, starches, salts) well.
In another bowl, lightly whisk the oil, yogurt, vinegar, and dosa batter until well combined.
Add the dry ingredients and the dosa mix to the yeast mix and whisk to combine well. The dough will be more of a stiff batter.
Let it rise for 1.5 hours or until doubled.(depends on yeast and ambient temperature)
The oats will make the dough less battery after the first rise, but it will still be sticky.
Add some starch or oats flour (1-2 Tablespoons)to make it less sticky/battery and dump the dough into parchment lined mini bread loaf pan. Even out using a wet spatula or wet hand.
For dinner rolls, use a combination of starch and oats flour and use oiled hands to quickly make small balls(a few Tbspns). Place balls touching each other in parchment lined stoneware for baking or round cake baking pan if steaming. See GF Dinner rolls.
For flat bread, pat the dough into ovals. Let rise, steam on stove for 10 minutes and grill on both side. See Gf Naan.
Spray the loaf top with water, and then with oil or dust with Oat flour.
Let sit in a warm place until doubled(20-35 minutes)
You can steam this on the stove top as the Oat sandwich loaf. Or in the oven as below.
Preheat the oven to 400 degrees F.
In a larger pan(I used the white stoneware pictured, any pan will work), add boiling water (1-1.5 inch high).
Place bread pan in the larger pan and seal the top with aluminium foil.
Prick a hole in the center of the foil and bake for 30 minutes.
Remove the foil and bread pan from larger pan, and place on regular oven rack, bake for another 10-15 minutes until the required crust color is achieved.
Let bread cool outside the pan for half an hour before slicing.
This bread tastes best toasted or warm and stays moist for 2-3 days. Store in the refrigerator, since steamed breads are usually more moist than regular baked breads.