Sautéing means to cook food (any food) quickly in a small amount of hot fat. (Stir-frying is a subset of sautéing.) Set a skillet over medium to medium-high heat and add some oil or butter — 1 to 2 tablespoons (more if you like) per pound of food. When the oil or butter is hot, add the vegetables and stir or toss them around in the pan until they’re cooked, seasoning as needed. Don’t crowd, or the vegetables will steam instead of brown. (For a specific example, see Pan-Grilled Corn with Chile, page 198.)
Stir-frying is one of the best and fastest ways to get an entire meal on the table, and, frankly, is a lot like sautéing, with bite-size pieces of food cooked in a small amount of oil over high heat. You can stir-fry just about any vegetable (and most other things as well): Cut the ingredients into more-or-less bite-sized pieces. If you want to include vegetables that take more than just a couple minutes to cook, like broccoli florets, for instance, they should be blanched first, to cut down on the time they’ll need when you start stir-frying. If you plan to serve your stir-fry with rice, have that ready, because the stir-frying itself is the last thing you do: Once you get started, the whole process moves quickly without any down time.