When my mother makes it she also serves mexican rice and corn tortillas. She also uses iceberg lettuce and uses it like a tortilla. Oh, and a sliced lime for any extra flavouring. I would imagine you could find most of this? I'm not sure about the tortillas but you can use wraps instead - which are very similar to flour tortillas.
If you wanted an appetizer you could do corn chips with pico de gallo or guacamole. Don't get a heavy one, though, or else you'll fill up on it. If you want to make it just remember to keep it light. To drink you can do anything you want.
Also, if you want the dish to look more colourful just slice up some bell peppers or tomatoes. Unless you're making green mole which is usually served a little differently. But I assume you're making brown mole? (should have asked this first