Turn the gas on. Turn on the fume hood and any other ventilation fans that the restaurant has.
Remove the panel directly below the oven door and find the pilot mechanism. The pilot light will be inside a small opening in the steel near the center. On many ovens this opening is labeled "pilot."
Twist the oven thermostat to the "pilot" position. Doing this will allow a small amount of gas to flow to the pilot hole in the pilot light but will not release it.
Push the thermostat forward -- it should slide toward the oven easily. This action will release the gas through the pilot hole.
Pick up an extended-reach lighter and click off the child safety mechanism. Light the lighter and hold the button down so the flame burns continuously.
Apply the flame to the pilot hole. The pilot light should light immediately. If not, check to see whether the gas is on and try again.
Hold the thermostat in for one minute. Check to see that the pilot remains lit.
Release the thermostat after one minute. If the pilot light goes out, turn the thermostat to off and wait two minutes for the gas to clear before attempting to relight it. If the pilot light continues to go out, turn off all the gas going to the oven and call a technician.
Twist the thermostat to the desired oven temperature. The action of turning the thermostat will release much more gas into the broiler underneath the oven, which the pilot light will ignite. The burning gas will heat the oven quickly.