Cut tofu into small pieces. Place in fine strainer and drain for about ½
hour. Meanwhile, boil large pot of water.
Rinse radishes, slice enough to measure ½ cup and then dice the rest.
Trim heavy stems from the mizuna, cut leaves into ½-inch sections, wash
well, spin dry.
Measure 1 cup tightly packed mizuna. Put in food processor with all but
2 Tbs scallions, the mustard and the salt. Pulse until fine. Add drained
tofu, lemon juice and zest, and 1 Tbs oil. Process until smooth, scraping
sides down. Refrigerate.
Cook noodles in boiling water until barely tender, 2-3 minutes. Drain
To serve, line bowls with whole mizuna leaves. Toss noodles with diced
radishes, reserved 2 Tbs scallions, 1 Tbs oil and shoyu. Divide among
bowls, then spoon the mizuna dressing over the noodles. Top with sliced
radishes and sesame seeds.