Preheat broiler to 500ºF.

Place peppers on a baking sheet. Char peppers on all sides under the broiler until the skin is blackened in most parts of the pepper and the pepper is soft.

Transfer peppers to a heat-safe bowl and cover (with a tight-fitting lid, plastic wrap or a kitchen towel) to let the peppers steam for about 20 minutes until the peppers are no longer too hot to handle.

Remove the charred skin from the peppers and discard. Remove the stem and the seeds and discard.

Either dice up the peppers or leave them whole and place in jars. 

Peppers are ready to use right away or kept for later. To store peppers, place in jars with a splash of olive oil and the pepper liquid. Let cool completely before storing it in the refrigerator for about 7-10 days.