Before we learn how to peel, slice and chop onions it is important to know the different types of onions and some of their uses.
Yellow onions have a sharp spicy flavor, but they also have a lot of sugar. When yellow onions are cooked they loose the sharp flavor and become sweet. Yellow onions have a yellow-brown papery skin on the outside and a white flesh on the inside. Their high sulfur content makes your eyes water.
Sweet onions (vidalia and walla walla) are best for frying, making onion rings, baked gratin, roasted vegetable dishes. A sweet onion has thick layers which makes it great for slicing into rings. It is sweet but not spicy. Great for a French Onion Soup because of its sweetness.
White onions are the crunchiest because of their high water content, sharpest, not very sweet, large, papery skin, mostly used in Mexican cooking.
Red onion is mild, best eaten raw, best on guacamole, salsa, pickling, sliced in salads, on burgers, in sandwiches, crisp a little sweet, adds a lot of color.
Shallots have the most subtle flavor, sweet with a little spiciness, great for an egg dish, vinaigrette, garnish.