Directions

Measure all the dry ingredients into a large bowl.
Use a coffee grinder to grind the rice, quinoa, millet, buckwheat, sesame seeds, and flax into coarse pieces. Do not grind the cornmeal and amaranth.
Stir everything until it is evenly mixed.
Keep it in a sealed container, or divide it into small zip-top bags.
To cook a single serving, bring the water and salt to a gentle simmer in a saucepan, then stir in 1/2 cup of the mix.
Turn the heat down to medium-low and cook for about 20 minutes, stirring often, until the cereal is thick and tender.

Notes

Dry mix: airtight in a cool, dry place; use within about 3 months of opening. Refrigerate cooked cereal within 2 hours, eat within 3 to 4 days; reheat with a little water or milk. Ground flax and sesame go rancid quickly at room temperature; fridge or freezer storage is safer. For gluten-free use, buckwheat, millet, and cornmeal should be certified gluten-free.

Nutrition

Nutrition is an estimate per serving from USDA FoodData Central, for 9 servings; brown basmati rice counted as dry brown rice, quinoa counted as dry quinoa, millet counted as dry millet, cornmeal counted as yellow cornmeal. Brands and portions vary, so use it only as an approximation.