Simmmer.

Step 1 of 5

Sundubu Jjigae (Soft Tofu Stew)

Step 1 of 5

Make the chili oil

Heat the vegetable oil in a small heavy pot over medium heat. Add the gochugaru and stir for 30 to 45 seconds until the oil turns deep red and smells toasty. Watch it closely — chili flakes scorch in seconds.

This one step is where the color and most of the flavor come from. Do not rush it and do not let it smoke.