Rinse rice and barley in a medium-mesh sieve, then drain and transfer to a 4- to 5-qt heavy pot. Add water (3 1/2 cups) and bring to a rolling boil. Reduce heat to low and cook, covered, 45 minutes. Remove from heat and let stand, covered, 10 minutes, then stir from top to bottom with a rubber spatula.
Korean food is among the most accessible of Asian cuisines, as relatively simple textures and flavors—garlic, chiles, the sweet meatiness of short ribs—add up to a complex, beautifully balanced whole.