Make the dressing by combining the first 7 ingredients in a small bowl.
Arrange the salad greens on a large round platter. Arrange the oranges in a slightly overlapping circle on top of the greens. Arrange the asparagus in the centre of the salad. Disperse the shrimp on top of the oranges. (The salad and dressing can be made to this point an hour or so before serving; cover and refrigerate until needed.) Drizzle the salad with the dressing and serve.
Note: To blanch the asparagus, plunge into boiling water 2 minutes and then drain. Immediately cool with ice-cold water, drain well, and the asparagus is ready to use.