Take a bottle of Italian Vinaigrette and a disposable aluminum pan with you. Put your vegies in a Ziplock bag, dump in some of the salad dressing, and toss. Put a big piece of foil in the pan for better insulation, spoon vegetables in and spread out, fold foil over the top, and put over indirect heat.
Or put the vegetables in a well-oiled iron skillet and cover with lid. They will take longer to cook this way, but won't burn so easily.
For vegies, I would suggest sliced potatoes, baby carrots, celery, onions, garlic, and brussels sprouts. These can be varied according to your preference, of course. If you have any bacon left from breakfast, crumble it over the top.
I would also consider roasting some foil-wrapped sweet potatoes in the coals.
They're delicious with pork, and only need a bit of butter mashed into them, as you would a baked potato.
You could also make fried apples...Just peel a few apples, slice and put in an iron skillet with butter. When the butter starts to melt, add sugar and seasonings (cinnamon, nutmeg, lemon juice) to your taste. Raisons and/or a shot of rum (preferably Myers) are optional.
*Important! If you use the rum, add it at the very last, and be sure to take the pan off the fire before you add it.
Alcohol is extremely flamable, and I don't want you getting burned!