1/4c bubbly sourdough starter (any water poured off)
1/4c sprouted brown rice flour
1/4c filtered water
Combine all ingredients. Pour into a well-greased ramekin (I use coconut oil) and allow to culture around 6 hours. Don't worry if it doesn't appear to rise; much of the rise will happen during baking. Place a metal pan or measuring cup of water in the oven (during baking, refill with boiling water if necessary). Preheat oven or toaster oven to 425 degrees. Place bread in the oven and bake until completely golden brown with no pale spots (about 45 minutes).
I'm fortunate to be able to buy sprouted brown rice flour in bulk at my local coop. Their source is Hummingbird Distribution, which serves the Pacific Northwest. Sprouted brown rice flour is also for sale on this website: http://healthyflour.com/product/organic-sprouted-brown-rice-flour/
Net carbohydrate is 41 grams, but this doesn't account for the starch eaten by the wee yeasties (nom nom nom), so this is a generous estimate.