Peel and segment grapefruits (see tip above). Squeeze the remaining grapefruit membranes over a separate bowl to capture about 2 tbsp (30 mL) additional grapefruit juice. Discard membranes.
Mix grapefruit juice with honey, cardamom and zest. Pour mixture over grapefruit segments, add pomegranate seeds and gently toss to combine. Let stand for at least 15 min. (or cover and refrigerate overnight). Add mint just before serving.
To create citrus fruit segments, simply cut off the top and bottom of the fruit and stand it up on one end. Slice downward to cut away the skin and pith, moving around until all is removed. Holding the fruit over a bowl, slice along the sides of each membrane to release segments.