Certain foods need to stay in contact with the pan awhile before you move them. Proteins like steak or chicken, or starches like potatoes and bread crumbs, need to cook until a sear forms. Put a steak or sliced potatoes in a properly heated pan and try to move it right away… it will stick. If you just wait a few minutes and then test it carefully, you’ll know when it’s ready to come away from the pan effortlessly, without tearing or leaving a layer behind.
If you’re making a braise or a stew, the meat should be seared first to create what’s called a fond, the brown (not black!) residue that forms. This is important for maximum flavor. Onions, celery, or other vegetables too need to take on some color for flavor. If you keep stirring them, they won’t have the opportunity to do so, and the final dish won’t be as savory as it could be.
When cooking a patty made of ground meat, don’t press down on it with the spatula. Doing so forces out the juices, and the result is a dry burger. Don’t keep turning it, either. Allow the first side to brown nicely, then turn and brown the other side. If it still needs more cooking to get to the doneness you prefer, lower the heat or move the burger to a cooler part of the grill. The same applies to a steak or cutlet.
Meats that come directly out of the pan, whether it’s a skillet or a roasting pan, or off the grill, need to rest before being cut into. The larger the piece of meat, the longer it needs to rest. A steak may only need five minutes; a large roast or bird can rest gracefully for half an hour or more, tented (loosely covered with aluminum foil.) This resting time allows the juices, which have been forced by external heat into the center of meat, to redistribute themselves throughout the entire piece of meat. Then all those juices won’t gush out when you cut into it; your steak or roast will be moist and flavorful.
When making stock with raw meat and bones, bring all the ingredients to a boil and then turn down to a simmer. For the first 15-20 minutes of cooking, don’t stir, but do skim off the grey, bubbly foam that forms. These are impurities from the meats which need to be removed so the stock will be clear. Stirring will break up the foam/crust and cause the stock to be cloudy.
When reducing a sauce, don’t stir continuously. Stirring lowers the temperature of the liquid, and the process will take longer.
With the exception of risotto, which should be stirred constantly, don’t stir or otherwise disturb rice when cooking. Doing so causes starch to leak from the grains and will make the cooked rice sticky.
Sometimes holding back is good cooking technique. Resist the urge to fiddle with your food unnecessarily, and you’ll improve your cooking appreciably.