1 small leek
3 or 4 pieces (about 3x6x¼ inches or 8x15x0.6 cm each) deep-fried tofu
1 quart (1l) boiling water
2 quarts (2l) water
14 ounces (400 g) dried udon noodles
3 cups (750ml) cold water
1½ quarts (1.5l) dashi
2 tablespoons (30ml) sugar
6½ tablespoons (97ml) soy sauce
3 tablespoons (45ml) mirin
½ teaspoon (2ml) salt
1. Cut leek diagonally into ¼ inch (6mm) thick slices.
2. Place tofu in sieve; pour boiling water over tofu, turning to rinse both sides. Drain; pat dry with paper toweling. Cut each piece tofu crosswise in half; cut each half diagonally into 2 triangles.
3. Heat 2 quarts (2l) water to boiling in large kettle over high heat. Add noodles, a few at a time, stirring gently to separate. When water returns to full rolling boil, add 1 cup (250ml) cold water; repeat 2 more times, using remaining cold water. When water returns to boiling, check for doneness; cook noodles until firm-tender (do not overcook). Drain in colander; rinse under cool running water. Drain; cover with damp kitchen towel.
4. Place tofu, 1 cup (250ml) dashi and the sugar in 2 quart (2l) saucepan; heat to boiling over medium-high heat. Reduce heat to medium; simmer 3 minutes. Add 1½ tablespoons (22ml) soy sauce; simmer until almost all liquid is absorbed. Remove from heat.
5. Meanwhile, heat remaining 5 cups (1250ml) dashi and 5 tablespoons (75ml) soy sauce, the mirin and salt to boiling in 2 quart (2l) saucepan over high heat. Add leek; remove broth from heat.
6. Place warm noodles in individual serving bowls, dividing evenly; top with tofu. Ladle broth carefully over center of tofu (so that some leek remains on top of tofu) to a level even with top of noodles. Serve immediately; pass seven-spice powder.