An improved cooking assembly and method is disclosed. The nacelle includes a displacement mechanism displacing on request a portion of the nacelle wall to modify the passage section of the flow outlet through which a major portion of the flow escapes, the displacement forming in the nacelle wall at least one opening through which a small portion of a leak flow, naturally escapes. Hence for such efficient and cost effective one-way communication applications, unidirectional fiber optic transceivers are useful.