Honest Food's roasted red peppers recipe comes with useful information on canning the resulting peppers, during steps five and six of the six-step process. The key to successfully canning roasted red peppers is to release entrapped air bubbles to ensure a vacuum-tight seal.
Honest Food suggests roasting red peppers over a smoky wooden fire on a grill, although a gas grill can provide excellent results. An open burner on a stove is also acceptable, as is arranging the peppers on a broiling pan and broiling them. Once the peppers' skins begin to char, place them in a paper grocery bag, and seal them so that they steam in their own juices for 20 to 40 minutes.
Once the peppers have cooled, remove their skins, stems and seeds by hand. Do not run the peppers under water, as this will lessen their flavor. Pour vinegar into a casserole dish, and dredge the peppers through the liquid before placing all of the peppers in a separate bowl. Sprinkle kosher salt over the bowl of peppers, and mix them together so that the peppers are evenly salted.
Pour a small amount of vinegar into some canning jars, and pack in the peppers, leaving between 1 and 2 inches of space at the top and removing as many air bubbles as possible. Seal the peppers in olive oil, leaving only a quarter inch of space at the top, and seal the jars.