One of Martha's favorite dishes, this recipe from New York City's EN Japanese Brasserie teams homemade tofu with a warm sweet-and-savory dashi-based sauce.
Divide tofu evenly between six 6-by-6-by-3-inch tofu boxes; set aside.
Place dashi, soy sauce, and mirin in a small saucepan and bring to a boil over medium-high heat; add bonito flakes.
Pour dashi mixture through a fine mesh sieve set over a medium bowl; let stand 2 minutes. Divide tofu in each box into 2 portions. Place each portion of tofu in a small bowl. Spoon 2 tablespoons of mixture over each bowl of tofu; serve immediately.