California rolls

4 nori sheets
3 cups (15 oz/470 g) Sushi Rice
8 teaspoons ocean trout or flying fish roe
1-2 Cucumbers, cut into thin, lengthwise slices
8 jumbo shrimp (king prawns), cooked, shelled, veins and tails removed
1-2 Avocados, peeled, pitted, and sliced
4-8 lettuce leaves, torn or sliced (optional)

1. Lay 1 nori sheet on a rolling mat and put 3/4 cup (4 oz/125 g) sushi rice on it. Spread rice over nori sheet, leaving 3/4 inch (2 cm) of bare nori at far side and making a small ledge of rice in front of this bare strip.
2. Spoon 2 teaspoons roe along center of rice, using back of a spoon to spread. Add lettuce if desired.
3. Lay 2 shrimp along center, with one-quarter of cucumber strips.
4. Lay one-quarter of avocado slices along center. Add one-quarter of lettuce.
5. Roll mat over once, away from you, pressing ingredients in to keep roll firm, leaving the 3/4-inch (2-cm) strip of nori rice-free.
6. Covering roll (but not rice-free strip of nori), hold rolling mat in position and press all around to make roll firm.
7. Lift up top of rolling mat and turn roll over a little more so that strip of nori on far side joins other edge of nori to seal roll. Use your fingers to make sure roll is properly closed.
8. Roll entire roll once more, and use finger pressure to shape roll in a circle, an oval, or a square.
9. Using a sharp knife, cut each roll in half, then cut each half in half again. Then cut each quarter in half crosswise to make a total of 8 equal-sized pieces. Cut gently to maintain shape.