Chinese chili oil is sold in bottles in Chinese and Japanese markets. To make your own, heat 1 cup peanut oil, sesame oil, or vegetable oil over medium heat. Add 1/4 to 1/3 cup dried red chiles. Cook, covered, over low heat until the oil turns dark red. Remove from heat and let stand overnight, then strain into a clean jar or glass bottle, discarding chiles. Store tightly closed.