To roast jalapenos:
Preheat the broiler in your oven. Place jalapenos on a foil-lined baking sheet and place under the broiler for about 10 minutes or until the top of the skin has charred. Turn the peppers over and broil for another 5 minutes or so until the other side has been charred. Remove from oven and place peppers in a ziploc bag so it can steam.
After about 15 minutes, remove from bag and peel the outer skin off so you are left with just the inner pepper. Feel free to remove any of the seeds you'd like. More seeds = more heat. Less seeds = very mild.