Roast for about 15 minutes, then turn. Smaller peppers like the ones shown here will only need one turn, and will be done in about ½ an hour. Larger peppers will need to be turned a few times, and roasted longer, 45 minutes should do it for those.
Remove pan from oven, and set aside to cool.
Once the peppers are cool and shriveled, peel off the skin and de-seed them. Avoid the temptation to rinse the seeds off, you will lose a lot of flavor that way.
Put your finished roasted peppers in container and pour the juices from the pan in with them, for extra flavor.
Notes
You can add olive oil, a little Kosher salt, roasted garlic or herbs to your roasted peppers if you like, but they will be quite tasty served simply in their own juices, as shown above.