Grill or oven: either works great.
Set to 450 degrees.
Place chilies on cookie sheet and bake for 7-9 minutes until you can see the skin blister. Flip over each chili and bake another 7-9 minutes until blistered.
Remove to old towels or newspapers to cool.
When cooled, you can leave the blistered skins on and seal in freezer bags and freeze. Good for up to one year. When thawed, peel the blistered skin off.
If you wish to eat right away, after cooling hold chili under running water and peel the blistered skins off. Then use in any favorite recipe. Don't have a good recipe?Just Google "green chili recipes" and you'll find thousands.
* when handling chilies, it's always best to wear gloves to avoid rubbing your hands to your eyes later. Not good.