0.5 c some kind of flour that has actual fiber in it, such as millet or flaxseed
1.75-2 c random other kinds of non-wheat flour, such as sorghum, potato, rice, tapioca, or corn
2 t xanthan gum
0.5 c dry milk powder
1.66 c water
3 T oil
1 t apple cider vinegar
2 T honey or agave
1.5 t yeast
... and then attempted to acquire any of the ingredients for this at the local supermarket. But the only gluten-free anything they had was a 1-lb box of pancake mix. So I bought that, and substituted it for the flours and xanthan gum. I probably should also have decreased the water and sweetener and/or increased the yeast, but on "rapid bake" it made a passable loaf of something that might have been bread and might have been cake, and went nicely with chili in any event.
Further experimentation is clearly necessary.