Squeeze 1 1/2 Tbs juice from lemon into small jar. Add 1/2 tsp ginger, 3/4 tsp salt, 1/4 tsp pepper. Shake until salt dissolves. Add 3 Tbs oil, shake to combine. Remove tough stems from watercress; divide leaves among 4 plates.

In large bowl, beat egg. Drain salmon, add to egg with remaining ginger, scallion, parsley, 1/2 cup bread crumbs, 1/2 tsp salt and 1/4 tsp pepper. Mix well and shape into 8 patties. In large non-stick frying pan, heat remaining oil over medium heat. Coat patties with remaining crumbs and cook until golden brown on both sides, 3 to 5 minutes.