This recipe is a modification of a higher calorie dish. I have included notes on why certain substitutions were made that hopefully can help you modify other recipes with similar ingredients. I have listed the original ingredient in the recipe, and marked candidates for replacement with asterixes. I have put replacement recommendations in the comments.
1-2 lbs sweet potatoes
2-3 large apples (any kind)
1/2 cup cream *
Nutmeg, cinnamon, salt and pepper
Peel apples, core, peel, slice and sautee with butter.
In the meantime peel sweet potatoes, slice thin.
Place slices of sweet potato in a casserole dish and season with salt and pepper, a little bit of nutmeg (1/4 teaspoon) and cinnamon (1/2 teaspoon)
Add cream (or milk, or soymilk).
Butter (or lightly oil) a gratin dish, and layer sweet potatoes on the bottom
Sprinkle caramelized apples over the potatoes
Add a layer of sweet potatoes
Cover with aluminium foil and bake in a 350 degree oven for approx 60 minutes, until tender.
Remove foil, add breadcrumbs and small knobs of butter (or butter replacement) and bake until the bread crumbs have browned.
Comments: a low calorie food, high in fiber and a good source of vit A (beta carotene), vitamin c and manganese, a good source of copper, vit B6, potassium and iron