Grilling directly over the high heat of a gas grill makes quick work of steaks or chops, poultry or fish and even vegetables. If the heat is too high and the food starts to char, simply turn the knobs to reduce the heat or (if you have set up separate heat zones as explained below) move the food to a cooler part of the grill.

Light grill. Turn on all the heat elements to high, close the grill lid, and let the grill preheat for 10 to 15 minutes.

Create two or three heat zones in the grill.  For a three-burner grill, turn one heat element to medium, and another to the off position.  For a two-burner grill, turn one of the burners to medium.  Some foods, such as seafood, are best cooked only over very high heat. Create just two heat zones on your grill, one with very high heat and the other with no direct heat.

Start foods over the highest heat, and move them to a more moderate area as they sear or if flare-ups occur. If your food is cooking too fast, or you want to convert the grill from direct-heat grilling to indirect-heat grilling, simply turn the appropriate burner down or off, depending on your needs. Keep foods warm over the area with no heat or in a pan set to the side.

Controlling the Heat with Gas
Properly regulating the heat is the secret to perfectly cooked foods from a gas grill. Most gas grills have a built-in thermometer that tells you the temperature inside the covered grill, much like an oven thermometer. 

If you do not have a thermometer, use this low-tech way of estimating the heat: Hold your hand about 4 inches above the fire, or at the point where the food will be cooking. Keep your hand there as long as you can and count. If you have to move your hand in less than

1 second: the fire is very high heat, about 450°F.

1 to 2 seconds: the fire is high heat, about 400°F.

2 to 3 seconds: the fire is medium-high heat, about 375°F.

3 to 4 seconds: the fire is medium heat, about 350°F.

4 to 5 seconds: the fire is medium-low heat, about 325°F.

5 seconds or more: the fire is low heat, 300°F.

For a more precise measurement, use a special grill thermometer that clips onto the grill, or an oven thermometer that rests inside the covered grill. 

Changing the heat level is as easy as adjusting the heat on your kitchen stove. Simply turn the knob to lower or raise the temperature. To keep foods warm, turn the heat element off; the residual heat will be enough to keep the food at a pleasing temperature.