Steamed Soy Milk Custard

Measure the cold soy milk in a quart-size pitcher and season it with the mirin and soy sauce. Add the nigari mixture and stir gently to combine. Try not to create any foam as you stir.

Choose between the autumn version and the spring version, then divide the mushrooms or the bamboo shoots and asparagus stalk among 4 to 6 heatproof 1-cup cups. Gently pour all but about 1 tablespoon of the soy-milk mixture into the cups, dividing it evenly. Leave the 1 tablespoon in the pitcher. Do not worry if some of the vegetables float to the surface, but do be careful not to incorporate air as you pour. Air bubbles will mar the final appearance of the dish, so bubbles on the surface of the soy milk should be lanced or dragged to the sides with the tip of a toothpick and removed.

Add the chopped mitsuba or sliced asparagus tip to the soy milk reserved in the measuring pitcher and set aside.