Simply asking what are the ingredients in this works. That’s a little formal for something as common as food, especially if you’re not looking to make it yourself. A simple informal option is What does this have in it? Or if you want to emphasize that you want to know all the things in it you can say What all does this have in it. The response can simply be It has nuts, berries, etc. Or you can say there are nuts, berries, ... in it.

You could simply ask "Can/could i have the recipe?"(if you wanted to know how to make the dish). If you want to be more specific about what is in a dish you could say"What ingredients does this dish/recipe contain?"