Slicing is the first step to most onion preparation. If you're not comfortable with it, you'd better start practicing--or else count on cooking only with pearl onions (the tiny kind).

Clean the onion:

• Slice off the ends. Cut just inside the hairy root end. Keep an eye on that end--you'll need to locate it in Step 3.
• Place the onion flat on an end and slice in half, along the axis. Peel off the dry, papery layers of onion--these can have a harsh flavor and are tough to chew.
• Place the onion halves face down on the cutting board.
  
  

  Hold the onion:

• Known in some circles as "the bear claw," this method of holding the onion is essential to precise onion prep. It has two strategies: one, secure the onion so that it doesn't slide around or fall apart as you're cutting; and two, keep the fingertips out of the way--so you can keep your fingertips.
• For easy reference, let's call the hand that doesn't hold the knife "the free hand." Place fingertips of the free hand on the top of the face-down onion half. Your pinkie and thumb should be next to an onion end.
• Push or roll those fingers forward so that the first knuckles are tucked in towards your palm.
• In doing so, the second knuckles of your free hand will be roughly square to the cutting board and at the edge of the onion. These knuckles will act as a guide for the knife.
  
  
  
  Slice the onion:
  
  
• Your knuckles are now at the edge of the onion. Pull the knuckles back a 1/2 inch, 1/4 inch, or an 1/8 inch ( 1 cm, .5 cm, .25 cm), depending on how thick you want the slices. Choose a slice thickness and stick with it--uniform slices cook evenly and look more appetizing.
• To maintain straight and even slices, rest the flat side of the knife against your knuckles. Make a slice parallel to the axis and straight down to the cutting board. Drawing the knife towards you slightly as it slices down will also help.
• Lift the knife up and away from you slightly, scoot your free hand knuckles back a 1/2 inch (1 cm), and descend again with the knife. This motion of lifting away and drawing toward will create a circular motion that's both rhythmic and efficient.
• Continue cutting until you're two-thirds done with the onion. Now flip the onion onto its other side, so that the uncut side is exposed. Start cutting the uncut side, using your first finger to support the remaining onion on its underside, and using the outside of your thumb as a guide.
  
  
  
  
• If this seems like too much at first, here's an easier way that produces decent results. At the halfway point, turn the onion a half turn (180 degrees) so that you're working on the other end. Slice this new, uncut end until you're at the center. Use your thumb and first two fingers to hold the final slice in place. (Hold them near the top, not at the bottom near the cutting board.)
  
  
  
  
• If even that seems like too much, here's an even simpler way. Slice the onion until it's too small to hold. Then turn the remainder a quarter turn (90 degrees), and slice the remainder. You're slicing the other way now (which some cooks forbid in their kitchen), but it's a good compromise if the other methods seem too precise for you.