Simmer the millet and quinoa in a saucepan with a 1:2 ratio of grains to water until fully cooked and the water is absorbed, about 20 minutes. Remove from heat and let rest for 10 minutes or so, with the lid on. Fluff with a fork and set aside. Chill, if serving cold.
Remove the pits from the cherries. (I recommend a cherry pitting tool or a helpful friend or family member)
Toss the rest of the ingredients together with the grains in a large bowl.