If you boil tofu rapidly for 30 minutes, it will fill with holes and become a sponge, “ready to squirt its sauce when you bite into it.” So says Sam Liang, the hero of Nicole Mones’ 2007 novel, “The Last Chinese Chef,” who hides a reduction sauce made from 30 crabs inside plain boiled tofu and wows the judges of a cooking contest.
When I read this passage, I filed away Sam Liang’s idea. But rather than use the spongy tofu to show off a complex and labor-intensive sauce, I simmered it and served it in a flavorful mushroom broth. The broth showed off the tofu and the thinly sliced shiitakes that are added five minutes before the soup is served, and the tofu showed off the broth.
My soup is not 100 percent Asian because I used dried porcini mushrooms, which are Italian. But they are my go-to mushroom when I want to make a rich-tasting broth; they produce a more intense broth than Asian shiitakes. I soaked the porcinis in boiling water, strained and diluted the strong infusion with more water, and completed the broth by simmering the shiitake stems, some rounds of fresh ginger and a split head of garlic for a half-hour.
I strained the broth, seasoned it with salt and soy sauce, added tofu and simmered it for another 30 minutes. Just as Sam Liang promised, the tofu became spongy, porous and flavorful, with the deep umami taste of mushrooms inside and out.
Tofu mushroom soup
1 ounce dried mushrooms (about 1 cup), preferably porcinis
1/2 pound fresh shiitake mushrooms
1/2 pound fresh button or cremini mushrooms, quartered
1 head of garlic, cut in half crosswise
2 teaspoons salt, or to taste
6 slices fresh ginger, from the widest part of the root
2 tablespoons soy sauce
14 to 16 ounces tofu (1 box), either firm or soft, cut in 1-inch dice
1/2 cup chopped cilantro
2 tablespoons chopped chives
1. Place dried mushrooms in a bowl or large heatproof measuring cup and cover with 2 cups boiling water. Let sit for 30 minutes. If mushrooms are sandy, agitate from time to time. Line a strainer with cheesecloth and place over a 1-quart measuring cup. Drain through the strainer, then twist mushrooms in the cheesecloth, holding them over the strainer, to squeeze out the last of the flavorful liquid. Discard reconstituted mushrooms or set aside for another use.
2. While porcinis are soaking, pull tough stems away from shiitake mushroom caps. Slice caps thin and set aside.
3. Combine the mushroom broth with enough water to make 9 cups liquid and place in a saucepan or soup pot. Add shiitake stems, quartered button or cremini mushrooms, halved head of garlic, salt and ginger slices, and bring to a boil. Reduce heat, cover and simmer 30 minutes.
4. Use a slotted spoon or skimmer to remove mushrooms, stems, garlic and ginger from broth. Add soy sauce to broth. Taste and adjust salt.
5. Bring broth back to a boil and add tofu. Reduce heat to a simmer or a gentle boil, cover partly and simmer for 30 minutes. Tofu will puff a little, and texture will become more porous and spongy.
6. Add thinly sliced shiitake mushroom caps, cover and simmer 5 minutes. Stir in cilantro and chives. Taste, adjust seasoning and serve.
Yield: 4 servings