Spread out a length of clingfilm to 30 x 30 cm. Arrange the slices of smoked salmon on to the clingfilm in a single layer so that they form a neat rectangle, approximately 15 x 25 cm. Spread the washabi mustard over the salmon, and then refrigerate while you prepare the rice. Put he rice in a saucepan and cover with salted water (approx 250ml). Add the rice vinegar. Bring to a boil and continue to boil over a medium heat until the rice has absorbed all the liquid. Then take the pan off the heat and leave to cool. If the rice absorbs all the water but remains uncooked, add a little more water - approx 50ml - but ensure you do not saturate the rice, or it will not stick together. Allow the rice to rest in the saucepan for 10 minutes minimum. Cover the smoked salmon with the sheet of nori seaweed. Brush with shoyu sauce to soften the seaweed. Once the rice is cooled, spoon a layer over half the seaweed, along one of the long edges. Then roll the layers up together starting at the long edge with the rice spread along it. Make sure you roll tightly. Keep the roll in the clingfilm to help maintain its shape, then chill in the refrigerator for a minimum of 1 hour. Once chilled, slice the roll into 8 mini rolls, each one roughly 3cm long. Place two rolls on each plate, turning the rolls so that they stand with the filling facing upwards. Top each one with 1/2 tsp salmon keta or caviar and a trimmed sprig of mizunp or chervil to serve. You can place small dishes with shoyu sauce, wasabi mustard and pickled mooli on the plate for dipping. This recipe makes approximately 6 little sushi rolls, so if you need more simply multiply the ingredients. Per serving: 586 Calories (kcal); 21g Total Fat; (33% calories from fat); 93g Protein; 1g Carbohydrate; 144mg Cholesterol; 3203mg Sodium Food Exchanges: 0 Grain(Starch); 13 Lean Meat; 0 Vegetable; 0 Fruit; 0 Fat; 0 Other Carbohydrates Converted by MM_Buster v2.0n.