。
She got the meal ready in next to no time.
Literal
She [topic-は] mere brief moment [during-の間に] meal's preparation [object-を] did.
ほんのちょっと ('just a moment') is a frozen phrase — ちょっと itself means 'a little,' and ほんの dials it down further to 'a mere instant.' の間に marks the time window during which an action takes place: 'within the span of a moment.' The construction 食事の用意をする ('do meal preparation') is the standard light-verb pattern for cooking-as-task-completion, contrasted with 料理する which emphasizes the cooking activity itself.