Prep: 1. Drain and cut tofu. 2. Slice scallions. Make: 1. Combine wakame with warm water to cover by 1 inch and let stand 15 minutes. 2. Drain in a sieve. 3. Stir together miso and 1/2 cup dashi in a bowl until smooth. 4. Heat remaining dashi in a saucepan over high heat until hot, then gently stir in tofu and wakame. 5. Simmer for 1 minute, then remove from heat. 6. Stir in miso mixture and scallion greens and serve.