Choose the Right Pan
The pan material affects cooking: stainless steel gives good browning over high heat, cast iron retains heat for a long time, and nonstick-coated pans work at low to medium heat but are not designed for high heat.
A thick-bottomed pan distributes heat evenly across the surface; a thin-bottomed pan heats unevenly, so some ingredients may burn while others remain raw.
Control the Heat and Test When the Pan Is Hot
Heat an empty pan over medium-high heat and add a few drops of water: if a drop evaporates immediately, the pan is not ready yet; if it beads up and glides across the surface (the Leidenfrost effect), the pan is ready to brown food.
Adding food to a cold pan can make it stick because proteins or starches bond with the cold metal surface. As the pan heats up, this bond releases on its own.
Choose the Oil and Consider Its Smoke Point
Each oil has a different smoke point; olive oil can handle medium-high heat, while sunflower or canola oil can withstand higher heat. When oil starts to smoke, it has broken down and can leave a bitter taste.
Add the oil after the pan is hot and spread it into a thin layer over the surface; too much oil turns sautéing into frying.
Add Ingredients in the Right Order and Amount
The most important rule is not to overcrowd the pan: ingredients should remain in a single layer. If piled on top of one another, steam gets trapped and the ingredients release their moisture and steam instead of browning.
Add firm ingredients that take longer to cook, such as onions and carrots, first; add quick-cooking ingredients, such as garlic, peppers, and leafy greens, later. Garlic burns and turns bitter if added too early.
When making a chicken or ground-meat sauté, prepare the raw meat on a separate cutting board and wash the same knife before using it on vegetables. Cook chicken to an internal temperature of at least 74 °C / 165 °F and ground meat to 71 °C / 160 °F.
If the pan is crowded, cook in batches; trying to finish everything in one go will leave you with a mushy result. Rushing is the enemy of sautéing: adding ingredients before the pan and oil are ready turns sautéing into steaming.