To saute is to cook a food quickly in a small amount of fat over a relatively high direct heat. First, heat the pan over a medium flame, then add your fat.
Once the fat begins to ripple, add your ingredient. Here we're using chicken breasts. It is very important not to crowd the pan or the liquid released from the food will actually cause steaming rather than sauteeing.
Any food to be sauteed must be tender to begin with. The cooking process is so quick that this technique will not tenderize foods.