1. Place sliced celery, broth, butter, peppercorns, and salt on a dinner plate. Cover with microwave plastic wrap. Cook at 100% for 2 minutes.
2. Remove from oven. Uncover and scatter celery leaves over mixture. Place fish evenly spaced, on top of celery. Sprinkle with lemon juice and celery seeds. Cover tightly with plastic wrap. Cook at 100% for 1 minute. (if using a small oven, cook for 2 minutes.)
To Serve . .Double ingredients. Divide ingredients equally between 2 plates. Proceed as for single serving, heating broth mixture simultaneously, using a rack for 4 minutes. Cook fish as in step 2 for 2 minutes.