Cốm (green rice) is immature rice kernels roasted over very low heat then pounded in a mortar and pestle until flattened. It can be eaten plain or with coconut. The taste is slightly sweet with a nutty flavour. A traditional pastry, bánh cốm (green rice cake) is made using cốm with mung bean filling. Cốm is often offered during ceremonies to worship ancestors in the Mid Autumn Festival.