This may sound cruel, but it won't hurt him. As long as you give him plenty of water still, he can go a day without food. The next day, hold the food in your hand, and his hunger will act as an incentive to take the food from your hand. If this doesn't work (which it should) then try cup feeding, and then eventually after he takes food from a cup, hold the cup in your hand and see if he takes it that way. Work with this, it will potentially take days and days, but eventually he'll probably warm up to you. Plus he's a panther.
I say to try giving him a day without food, but I cannot stress enough, give him WATER EVERY day. And don't go more than one day without any food. In the wild chameleons obviously may go a day or two without any food, as feeding them with a specific schedule like we do is a bit unnatural. This is why it is okay to go a day without feeding him, but I wouldn't extend that any further.
edit: Oh and lastly, once he starts taking it from the cup in your hand, or straight from your hand if you're at that level, try holding another hand in front of him, slowly, with no movement. Your arms will ache and go numb, but he just might walk right on your hand to reach the food if the food is far enough away from him, but where he can still see it. Especially if he didn't eat the previous day.

This is what I did with my chameleon, and now he walks on my hand a lot more frequently.