Place shiitake in a saucepan with water to cover and bring to a boil. Reduce heat to low, add shoyu and maple syrup, cover and simmer 20 minutes. Remove shiitake and place in a small bowl. The shiitake cooking water may be chilled and used as a dipping sauce for the sushi.
Take a sushi mat, set it on the counter or cutting board. Place a sheet of sushi nori on the mat with the rough, dull side facing up. Take 1 to 1 1/4 cups of cooked rice and spread it evenly on the bottom half of the sheet of nori. Moisten a wooden spoon or rice paddle and press down firmly on the rice to evenly spread and cover half the sheet of nori. Place several pieces of shiitake, in a straight line, across the center of the rice (horizontally). Place 3 or 4 slices of avocado on top of the shiitake, in a straight line. Pull the mat up with your thumbs, hold and tuck avocado and shiitake with all eight fingers. Roll forward in a jelly roll fashion, and tuck the nori forward, while pulling back the mat slightly each time you roll forward. Just before you reach the end of the sheet of nori, moisten the end with a little cold water. Continue rolling until you have a cylinder shaped roll. Tightly wrap the mat around the roll, and squeeze gently to seal the nori roll. Remove the mat and place the roll on the cutting board.
Moisten a sharp knife with water and cut the roll in half. Cut each half in half, then each quarter in half, moistening the knife each time before cutting. You should now have eight equal size pieces of sushi. Repeat the above steps until you have 6 rolls or 48 pieces of sushi.
Try mixing a little E_span class="brand"_den_/span_ Wasabi Powder (Japanese Mustard) in with the shiitake cooking water before chilling and using as a dip sauce.
Per serving - 321 calories, 5 g fat (15% calories from fat), 7 g protein, 60 g carbohydrate, 4 g fiber, 0 mg cholesterol, 176 mg sodium