For 2 cup of Red pepper oil:

2 cup vegetable oil
2 cup chili powder
2 dried chili, sliced
1/2 stalk leek, sliced
1/3 ginger, sliced
2 cloves garlic, sliced
1/2 onion

1. Heat vegetable oil just until you could feel the warmth. (Do not bring to boil.)
2. Add the ingredients above.
3. Simmer in low heat for about 10 minutes.
4. Remove from heat just before the color turns dark.
5. Drain oil
6. Store in a glass bottle and keep in a cool shady place.

I extracted only 1/3 of the original volume of the oil.

(Adapted from