Bring brown rice, quinoa, amaranth, millet, wheat bran, salt, and water to a boil in a medium pot.
Reduce heat, partially cover, and simmer, stirring occasionally, until cereal is the consistency of porridge (softer and thicker than the usual bowl of oatmeal) and water is absorbed, 40–50 minutes.
Recipe Notes
NOTES
Do Ahead: Porridge can be made 5 days ahead. Let cool; cover and chill.