Onions are the most commonly used vegetable in the kitchen so we must learn to efficiently break them down The goal is a form we can be easily managed and processed. 

The first step is to peel off the outer layer of the onion skin and "Trim" it, as Teaching Chef demonstrates. Notice, how Teaching Chef cuts the Onion in half through the root. We always cut Onions through the root so that the root can help hold the "Rings" together. With everything held together for us by the root, we can make finer cuts.

So when you have "Previewed" and "Processed" and are ready to "Practice" peeling the Onion, make sure you don’t cut the root off. Trim the outer layer of the Onion. In the peeling phase, you should not experience too much eye irritation. If you do, many cooks peel / cut onions next to cold running water to help avoid potentially irritating onion fumes from the combination of the enzyme sulfoxide lyase with sulfuric compounds. Another more costly alternative is one your friends may tease you about, but that also works: Onion Goggles.

Once the onion is cleaned and peeled, it's ready to work with. By the way, the technique demonstrated applies equally well to Shallots.

Again, if you have an interest in building your Taste Pallete you may want to try a small bite of the Raw Onion and file that taste away for later reference. Get comfortable Peeling Onions, before moving into Peeling Mushrooms.