Plot Gods decree you can only eat either hamburgers or hot dogs/sausages for the rest of your life. This is not exclusive of other foods, but one becomes forbidden.
The up side is that you get a magical supply of the one you choose. Just wave your hand and either the perfect hamburger, or the perfect hot dog/sausage, appears before you.
The meat is always top quality, always prepared to specifications. The buns and fries and condiments are perfect, and of the most healthful quality.
You can manifest enough food to feed a family of twelve daily.
But... you can never eat the opposite of what you choose.