Preparation

• Cut off both ends of one of the grapefruits. Stand it on one end and cut off the peel and the white pith to expose the flesh. Slice the membrane, letting them fall into a small bowl. Squeeze the juice from the membrane into a 1-cup liquid measuring cup; discard the membrane. Cut the grapefruit segments crosswise into 4 pieces. Drain the pieces and add the juice to the measuring cup. Juice the remaining grapefruit and add enough of it to the reserved grapefruit juice to yield 2/3 cup. Refrigerate the grapefruit segments and watermelon pieces separately.

  在一个中等的无反应碗中，将扇贝，葡萄柚汁，柠檬汁，红洋葱和哈瓦那人混合在一起。盖上并冷却，直到扇贝不透明，大约30分钟。

  Drain the scallop mixture in a fine sieve and transfer to a large bowl. Gently stir in the watermelon, grapefruit, and parsley. Season to taste with salt and pepper. Serve cold on small plates or in bowls.