Here are some very simple, reasonably healthy, child-friendly GF/CF meals, which don't require a lot of "specialty" ingredients:
Two sweet potato ideas:
1) Baked sweet potatoes, topped with flaked canned salmon (or tuna) and a little olive oil.
2) Hamburger patties served with sweet potato "oven fries" (peel, cut in fry shapes, toss with paprika, salt, & oil, bake ~30 min at 350).
Meatballs and rice:
Put rice on to cook. Meanwhile, mix together 1 lb. ground meat, an egg, 1 - 2 tbsp. of GF breadcrumbs (or 1 rice cake, finely ground in a blender or food processor), and your choice of seasonings.
Shape mixture into meatballs and cook in a pan on medium heat, adding a little oil if you're using lean meat. You can also add some chopped onions, sliced mushrooms, or chopped leafy greens to the pan, if you like. Reduce the heat if the food starts to brown too much.
When meatballs are cooked through, add about 3/4 cup stock; scrape pan to loosen stuck-on bits. Thicken the sauce with a teaspoon of arrowroot flour mixed with a little cold water. Serve over rice.
Fish and chips:
Arrange plain white fish fillets, such as cod or sole, on a baking pan. Sprinkle with seasonings, a little oil, and some breadcrumbs (see above). Bake at about 400 degrees, along with a pan of oven fries. Timing will depend on the thickness of the fish. For thin fillets, you might have to start the fries a bit earlier than the fish.
Serve with your choice of steamed vegetables. Peas and carrots will add a dash of color.
(BTW, we've tried the "Ian's allergen-free fish sticks," but they're expensive and, IMO, revolting. Same goes for their chicken nuggets.

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Beef or lamb stew:
Dredge beef or lamb cubes in a mixture of sweet rice flour (e.g. Mochiko or Trader Joe's brand), salt and pepper. Heat some oil in a medium saucepan, and saute a chopped onion and a whole garlic clove. Add the meat and cook until lightly browned. Add stock or tomato juice to almost cover the meat. Simmer for about an hour.
Add chunks of vegetables of your choice (carrots, celery, turnips, potatoes, sweet potatoes, etc.), and some chopped fresh parsley or other herbs. Simmer until vegetables are done.
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