Reversible lid (1) for a storage or reheating canister, comprising a first (2) airtight attachment means designed to cooperate with an upper edge (4) of a container (5) when the lid (1) is arranged along a first direction on the container (5) and a second (3) airtight attachment means designed to cooperate with said upper edge (4) of the container (5) when the lid is arranged in the reverse direction on the container (5), characterized in that the lid (1) comprises a two-way steam release mechanism (10), connecting the two opposite surfaces of the lid, and in that said two-way release mechanism (10) allows a flow to pass between the two surfaces of the lid (1) when the pressure difference between the two surfaces is greater than or equal to a value (P0), particularly when reheating food in a microwave oven.