Many people may connect this Lake Merritt sushi joint with the eccentric owner and his endless sake, but it also serves a Japanese delight that's uncommon in East Bay eateries: chawan-mushi. Pronounced chow-won-moo-shee, the savory dish is part custard, part soup. The base of the stock is dashi (a mixture of water, kelp, and bonito available commercially in instant packets) mixed with eggs, soy sauce, mirin, and salt, which bakes into a semi-solid custard. When stirred with a spoon, the egg that has risen to the top breaks up and mixes with chicken, shrimp, bamboo, mushrooms, and kamaboko (processed fish cakes). It's possible to serve as a dessert because the eggs add a touch of sweetness, but it usually appears as a soup course. If you've never had it, the cups hold a great surprise sure to defy your expectations. Aside from being delicious and intriguing, the custard is a great conversation starter that has proven to light up the eyes of friends and strangers who grew up in Japan.