To peel or not to peel? Your mother’s admonition that the peelings of fruits and vegetables is full of vitamins wasn’t far off. Apples, for example, supply much of their fiber through their skins although, to be honest, less than half the fiber is found there.
Brightly colored carrots have far more of the important beta carotene in their flesh than they do in the skin (For that matter, if you peel any vegetables whose skin is the same color as the flesh, the amount of vitamins you’re losing is minimal at best). Potatoes? Again, despite your mother’s warnings, you’ll still find the majority of nutrients in the potato itself, although it’s worth noting that when you boil a potato in its jacket, you’ll retain more of the good stuff than if you had peeled it first.
A good swivel-blade peeler with a comfortable handle – such as an Oxo brand peeler, or one of its many knock-offs – is your best friend, particularly if you find yourself peeling large quantities of fruits and vegetables. Those old-fashioned narrow, metal handled peelers work fine but for sheer comfort, it’s worth spending a few extra bucks on something that won’t leave your fingers and hands feeling cramped. You could use a paring knife, as well, but for sheer ease, stick with the peeler.
Otherwise, there are two good reasons for peeling your fruits and vegetables. First off, esthetics. Your dishes will often simply look better when the ingredients are cleaned up a bit. Second, taste. On some vegetables, the skins can be bitter and removing them enhances the flavor.
Bell peppers and chilies are two vegetables that change dramatically when peeled. The light, almost paper like skin that coats them is quite bitter; remove it and the natural sweetness of the peppers comes through. Doing so, however, takes a bit more than just a vegetable peeler.
Peppers are most easily peeled after their skins have been charred, either on a grill, over the burner on your stove, or – easiest – in the oven, roasted at 400 to 450 degrees. Charring them, over a flame or on a grill, however, imparts a wonderful, smokey flavor that can be a nice addition to the dish you’re preparing.
Crank up the flame to high and then place the pepper in the middle of the burner, letting it rest on the metal rack that supports the pots and pans you’d normally put there. As the skin on the pepper chars, turning black and crisp, turn the pepper over so that its entire surface is gradually exposed to the flames. Once it’s charred completely, drop the pepper into a resealable container or a zip-lock bag and let it remain there for about 15 minutes. The steam produced by the heat will loosen the skins from the flesh, making them easy to remove. You’ll want to remove the skins over a sink or bowl, however. It’s not a tidy task.
Not Craig Claiborne's Kitchen Primer 