A balanced diet, and certainly no burnt food- unless you had a Fire type, they tend to do that themselves at times; or at least a few do. Given Sobble is a Water type, you don't have to worry about that.

[A hand lifted, adjusting glasses idly-] Ah, yes, before I forget.

Young Sobble here may have a sweet tooth, as is common amongst pokémon. If he seems to, just be sure not to allow any sort of over indulgence.