Put the walnuts in a bowl and cover with cold water. Let stand for 1 hour. 2. Meanwhile, in a small heatproof bowl, cover the dried shiitakes with the boiling water and let stand until softened, about 15 minutes. Rub the porcini to remove grit; transfer them to a small bowl. Reserve the soaking liquid. 3. Cut the crimini mushrooms in quarters. 4. In a bowl, whisk together the tamari, olive oil, nutritional yeast, lemon juice, rosemary and miso. Add the mushrooms and toss to coat thoroughly. Let stand for 15 minutes, tossing occasionally. 5. In a small saucepan, combine the soaked shiitakes and sun-dried tomatoes. Slowly pour in the shiitake soaking liquid, stopping before you reach the grit at the bottom. Bring the liquid to a boil, cover and simmer over low heat until the tomatoes are tender, about 4 minutes. 6. Drain the walnuts and transfer them to a food processor. With a slotted spoon, transfer the marinated portobellos, porcini and tomatoes to the processor; puree to a coarse paste, adding about 1/4 cup of the cooking liquid adjust as needed to achieve desired consistency. Season with salt if needed.