There is, but you have to be 100% absolutely consistent to make it work.
You need to reschool him to pay attention to a small squeeze or tap with your leg. This is simple. Carry a big stick. Ask him once to move forward with your voice and a little squeeze. Nothing else. No leaning forward, no clucking, no squeezing his guts out. Ask a second time with voice and a little tap with your leg. Ask a third time, and immediately after your leg aid, put your reins in one hand and use your stick, *hard* behind your leg until he shoots forward. Praise him, and repeat. Then do lots and lots of transitions with the same method. Little tiny ask, medium ask, then use the stick until he shoots forward. Pretty soon he'll be listening for the little ask.
You have to be very consistent and disciplined for this to work. You can't get sucked back in to thumping with your whole leg or squeezing and holding the squeeze for 5 - 10 seconds. It's voice-squeeze, voice-tap, then all heck breaks loose, make him gallop forward. You want him to absolutely know down to his bones that if he hasn't responded by the third ask, things are going to get hot, no exceptions.
AND, as gypsygirl mentioned above, you can't grab the reins when he shoots forward. ANY forward is good at the beginning of the process when you're trying to get him to wake up and pay attention to your leg. You'll refine what forward means once he's responding consistently.
A good test for whether or not he's listening and in front of your leg is the transition between walk/lenghtened walk and trot/lenghtened trot. If you don't get an immediate response for lenghthened walk, even when walking away from the mounting block, you need to go back to the exercises above.