This is an important process for many of the great dishes in Mexican cuisine. It is an art, but we all have to start somewhere. I find that the oil water combo is best for making sauces because it develops the flavour and really softens the chile well. You can use only oil or only water if you like.
Step A. Remove all the seeds and veins, and any of the stem. You only want the leathery beauty of the chile itself. I have found using scissors for this very useful.
Step B. Heat a small bit of oil of choice in a fry pan. Use an oil that won’t carry a flavour…grapeseed is always my personal choice because it is flavourless and is happy at high temperatures (doesn’t turn carcinogenic like some others). Heat the pan to medium high heat.
Step C. At the same time have a pot of soft boiling water ready.
Step D. A few at a time, fry the chiles. Use tongs and turn and remove, putting in the pot of water. Be very careful not to burn them. You are aiming to cook them about 10 seconds or less. You only want to release the flavour, golden them…but it is so easy to burn them, and if this happens start again.
Step E. Cook the chiles in the water a few minutes to soften. Reserve the liquid