I use gluten-free flour that’s primarily a mix of tapioca flour, garbanzo bean flour, and potato starch as well as some sorghum flour and fava bean flour.
To get corn-free baking powder, I make my own. Mix 2 parts cream of tartar with 1 part baking soda.
Buckwheat is a gluten-free, grain-free seed related to rhubarb. Buckwheat grows as a flowing plant and the seeds are very nutritious. Kasha refers to the buckwheat kernels or groats that have been roasted. Kasha can be eaten as a hot cereal.