Place 2 pots of water on to boil: 1 pasta pot with a few inches of water in it, 1 medium sauce pan with 1 1/2 cups of water in it. Cover both pots and bring all the water to a boil.
When the smaller pot of water comes to a boil, stir in rice and return water to a boil. Reduce heat to simmer. Place a colander over the pot and add the edamame to it. Place the pot cover over the edamame nesting it in the colander. Steam the edamame 5 minutes, then remove them to 2 small bowls, salt them and cover bowls with plastic or foil to keep warm. Set colander aside and return pot lid to rice, stirring rice before replacing the lid.
While the edamame are steaming, before removing them to the bowls, you have a pocket of time to work with. Add 1/2 cup, a couple of handfuls of Napa cabbage to the second pot of water. Blanch the shredded cabbage 1 minute and remove with a spider or tongs to paper towels to drain and cool. Chop shredded blanched cabbage. Combine meat, chopped salad shrimp, sake, ginger, 1 scallion, 1 tablespoon tamari, sesame oil, black pepper and cooled, chopped cabbage in a bowl. Place 2 teaspoons of filling on each won ton wrapper. Wet your fingertips to help seal won ton wrappers. The gyoza should look like small half moons.
Place 1 or 2 Napa cabbage leaves into the bottom of the colander. The leaves will prevent your dumplings from sticking to the surface of colander. Arrange dumplings on Napa leaf in colander and steam over second larger pot of simmering water. Place large pot lid over the colander to trap the steam. Dumplings need to steam 10 to 12 minutes. While you are working on this, go back and forth with the edamame as necessary per above directions.
While dumplings work, slice the fillet steaks thinly across the grain. Toss with seasoning and teriyaki or tamari and sherry. Heat a nonstick skillet over high heat. Add oil and the meat and stir-fry. When meat browns at edges, add scallions and cook 2 minutes more, stirring frequently.
Use remaining raw shredded Napa cabbage as a bed to serve your dumplings on. Plate all of your items on little dishes and in small bowls.
Mix dipping sauce of tamari, mustard and vinegar for the gyoza and set out alongside dumplings.
Warm or cold sake, leftover from cooking, is the perfect beverage and chilled navel oranges or tangerines make a refreshing end to this meal.