i once used a cursed ring of sustainence(sp) with effects from S. Kings' Thinner. the only way to get it off was to pass it off to an innocent. or counter it with a normal ring of sustainence. which took up both magic ring slots. not so much food but similar.
Well, just pick your favorite fruits (ie, apples, oranges, etc.) and give them magic potion effects. Or, for that matter, make them enchanted with whatever spells you deem necessary. So instead of drinking a healing potion, the PCs can eat a healing mango.
Of course, this being Ravenloft, some effects might require that the PC eat a live maggot, roasted scorpion, allegedly-lethal mushroom they hope has been detoxified by the magic, etc.
"Who [u]cares[/u] what the Dark Powers are? They're [i]bastards![/i] That's all I need to know of them." -- Crow