01 - Using a sharp knife, slice off the tops and bottoms of each orange and grapefruit. Following the curve of the fruit, cut away all peel and white pith. Cut the fruit into thin rounds or supreme into individual segments, then set aside.
02 - Halve the avocado, remove the pit, and peel away the skin. Slice the flesh into thin, even wedges and set aside.
03 - Peel the red onion and slice it paper-thin into half-moons. Separate the rings gently and reserve.
04 - In a small bowl, combine the olive oil, lemon juice, honey or maple syrup, and Dijon mustard. Whisk vigorously until emulsified, then season with sea salt and freshly ground black pepper to taste.
05 - Spread the mixed greens across a large serving platter, creating an even foundation. Arrange the citrus rounds and segments over the greens, followed by the avocado slices and scattered red onion rings.
06 - Scatter the pomegranate arils and crumbled feta evenly across the assembled salad.
07 - Drizzle the prepared dressing evenly over the entire platter. If desired, finish with torn fresh mint leaves and a sprinkling of toasted pistachios or walnuts. Serve immediately.