We purchased a 240V 30amp griddle with a NEMA 6/30 plug config. Our electircian wired with 4 wires. Which wires go where. The receptacle only has 2 poles and a ground.

The two poles as you call them will be the red and black. No difference which side. What you called the ground pole will be the green wire IF the griddle has the ground wire connected to the metal frame of the unit. That would mean that the griddle was 240 volt only and didn't require a neutral. A make and model would help confirm the connections.