If you want to get good at cooking, I wouldn’t start with a recipe. I would get a cutting board, a good knife, and an onion. A lot of times when people are just starting out, they try to cook as many different things as possible. They think that if they cook as many different meals as they can, somehow they will learn how to cook. The reality is, the way that you gain control over the cooking process is by repeating it with the same ingredient. I use an onion because it requires you to make several different cuts. You have to slice the onion, then you have to dice it. You also have to learn how to hold onto the onion. If you cut the pieces too big or too small, they will cook at different rates, which can be instructive when you heat them up in a pan. So again, I would use this exercise as a deliberate practice rather than trying to make lunch.
Trim the ends off, cut the onion in half through the root, and lay it on its flat side. Let the tip of the blade rest on the cutting board as you arc the blade upward in a smooth motion. For now, don’t worry about speed. Just try to cut slices of relatively uniform thickness, even if it takes a while and feels a bit clunky. A productive fifteen-minute practice is to slice an onion, gather the slices together, and then slice them into strips of uniform width. You’ll build the same muscle memory without needing another onion.
Forcing the blade down instead of using the weight of the blade to slice down and through will result in crushed edges, slipped blade, and an exhausted hand. If the knife gets stuck, or the onion starts to collapse, ease up on the pressure and allow the sharp blade to do the work. A second error is curling the guiding fingers too late, exposing fingertips and hampering the motion. To correct, stop, pull your hand back into a claw and continue slowly, until the right positioning becomes instinctive. Take small moments to correct the little things that have greater importance than speed.
If you find your slices are getting thicker or thinner, pause, pull out the last few slices you cut and look at them. Place them next to each other and see where the misalignment started. You’ve probably rotated your wrist or allowed your guiding hand to slip back. Correct your position, and you’ll be back to slicing evenly long before you would have if you kept going. You get immediate feedback from what you see on the board. Nobody has to tell you what’s going on.
With enough practice, you will find the onion breaking apart in perfect little pieces, that are all roughly the same size, and that will cook nicely and look like they were meant to be cut that way, rather than like a mistake. This is the stage at which most new cooks abandon the exercise and move on. To make the motion reliable, repeat it the following day. Soon, the motion is automatic, and eventually, you apply it to carrots, peppers, herbs, and finally, entire recipes. You come to realize that patiently practicing with one ingredient had silently transformed all of the food you were to make.