If your child likes gravy, be sure to make your own and freeze leftovers whenever you prepare a turkey or a roast. Gravy, frozen in ice cube trays, is particularly convenient when you need just a little to put on meatballs or some mashed potatoes. A tasty filling can be prepared by combining cooked meat with onions and moistening it with a little GF broth or salsa. Even if you sneak in some cooked vegetables, they will probably be eaten without complaint. If your child is sensitive to texture, process the dip thoroughly in a blender or food processor.
Dips are another good place to add some vegetables that have been blended until imperceptible.
Fruits and vegetables contain many of the same vitamins and nutrients, but since fruit also contains sugar, they are far more likely to be eaten and enjoyed by your child. If your child will eat fruit but not vegetables, serve fruit with every meal. Even if your child will only eat one fruit, serve it often. As the opioids leave his system, it's likely that he will accept additional fruits very soon. Finally, look to other cultures and cuisines for ideas about serving dinner for your family.