Combine the red chili pepper powder with water in a stainless steel bowl. You need to wet it so that it can take the heat of the oil later. You can mix the water into the ground chili pepper with your hands. Use kitchen gloves. A stainless steel bowl is required because of the hot oil later.
⅓ Cup Red Chili Pepper Ground, 1 Tablespoon Water
Prepare the fresh ingredients. Make sure that your clean onion stalks are dry and not wet. Cut them into 2-3 inch long pieces.
20 Piece Green Onions
Peel ginger and cut into thick slices. Take off stem from dried chilies and discard, break or cut chili into two to 3 pieces. Keep fresh ingredients aside.
2 Inch Ginger Fresh, 5 Piece Red Chili Pepper
Pour oil into a small pot and take it to the heat. Keep over a medium heat setting.
1½ Cup Oil
Place green onion stalks, chili and ginger with Sichuan peppers into the oil. Make sure they are all submerged and stirred in.
20 Piece Green Onions, 2 Inch Ginger Fresh, 5 Piece Red Chili Pepper, 1 Teaspoon Sichuan Pepper
Cook to infuse the oil with the ingredients for about 10- 15 minutes. Watch it, it shouldn't be too hot and bubbling too hard, and it shouldn't cook too slow. Keep over a medium heat setting. The oil is done infusing when the onion stalks have turned crispy.
Take out the green onion stalks, ginger and chili pieces. You can use the green onion stalks in your food, the rest can be discarded. The Sichuan peppers can stay in the oil.
Keep the oil over a medium heat setting and check with a food thermometer. Increase heat if necessary to reach 350 Fahrenheit or 180 Celsius. Once you get there, take the oil from the stove. Do not heat it more because it can get to smoking point which isn't food save and too hot oil over the ground chili pepper will burn it and alter the taste.
Pour a spoon or two of hot oil into the prepared ground chili pepper in the stainless steel bowl and carefully mix it in.
Pour remaining hot oil carefully into the bowl. It will bubble! Mix it all in, cooking chopsticks are a great tool for this!
Let it sit for 10 minutes or so, and then pour your infused rayu chili oil into a clean jar. Close with a lid and store in a cool and dry place away from direct sunlight or use in your food directly.
Video
Notes
1 serving = about 1-2 Tbsp. This recipe makes about 30 servings, and the base recipe is a jar of 10 ounces or 300 ml. These are just estimates.