Bake or poach salmon until opaque and flakes easily with a fork. Set aside to cool. Chop in bite-sized pieces.
For dressing, simmer rhubarb in a saucepan with water until tender, about 10 minutes. Pour mixture into in a blender, along with ginger, mustard, and honey, and puree until smooth. Allow to cool.
Pour into a blender and add remaining ingredients, except oil. Process mixture together until smooth. Slowly drizzle in 2 tablespoons of the oil. Add more oil until you get the consistency you desire. Season to taste with salt.
To serve, divide the salad ingredients into four bowls and drizzle with dressing.
Notes
For low carb, replace honey with liquid stevia to taste