Bok choy is a delicious cruciferous Chinese green that happily is now pretty much available everywhere. Miso, rice vinegar, sake, sugar, and soy sauce are used in an endless variety of combinations for sauces... in Japan. This more westernized version of steamed bok choy uses fresh lime juice instead of vinegar for a floral tang that is the perfect complement to this sweet vegetable.
In a small saucepan, boil the vinegar mixture for 5 minutes. Add the sugar and stir, cooking until it dissolves. Reduce the heat to low, and with a small whisk beat in the miso paste and soy sauce, until smooth and well blended.
Beat in the lime juice 1 teaspoon at a time, tasting as you go for the desired amount of citrus. The sauce should be thick and creamy but not solid. If it seems a little stiff add the water to it, a teaspoon at a time. Set aside, cover and keep warm.
Meanwhile, bring 1-inch of water to a boil in a large saucepan. Place a steamer basket in the saucepan, then lay the bok choy leaves into basket, sprinkle with a little salt and steam until the greens are wilted and the white stems are just tender, about 3-5 minutes.
Remove the steamer from the heat and arrange the bok choy on a platter. Stir the sauce and spoon over the bok choy. Eat immediately!
Baby bok choy are usually about 2½ to 3-inches long. If you only find the bigger, longer bok choy, then trim off the root ends and cut the stems diagonally into thick 2-inch slices. Put the thicker white parts in the steamer first. Cook for 3 minutes then add the green tops and cook for 2 minutes more.
If you don’t have a steamer, bring about 1-inch of salted water to a boil either in a wok, my personal preference, or in a wide sauté pan. Stir-cook the greens in the boiling water until the white stems are just tender, about 3-5 minutes. Lift the bok choy out of the water and quickly drain on paper towels before arranging on a platter.