The phrase "millet mixture" refers to a combination of different types of millet grains. Millet is a type of small grain that can be used in cooking, and a mixture of millets means that different varieties of millet are blended together.
Add the millet mixture, salt and toss well cooking over low flame for 1 to 2 mins till they all get combined well and the millets get heated up. (ticklingpalates.com)