The key to successful sautéed vegetables is a very high heat. Use a wok or a large skillet (preferable cast iron). Keep the pan hot - at medium-high heat - to avoid sticking. Use just a little bit of virgin olive oil, and above all else, be mindful of the different cooking times required by different vegetables. Begin with the vegetables that take the longest to cook first. And if you're throwing in root vegetables like potatoes, make sure they're cut into small pieces so they cook more efficiently. Wash your vegetables, but be sure they're dry before placing them in the pot. Water is the enemy of cooking oil. Cook until lightly browned on the outside - you don't want to wilt the vegetables. Finally, remember not to over-fill the pan...this will reduce the heat and cause the food to steam instead of sear.