King Oyster Mushrooms with Pistachio Purée

Ingredients

• 6 tablespoons canola oil divided
• 3.5 ounce enoki mushrooms 
• 2  garlic cloves smashed
• 0.3 cup dashi powder instant (also called hon dashi)
• 0.5 lb jerusalem artichokes (also called Sun Chokes)
• 1.5 lb king oyster mushrooms (sometimes called Trumpet Royale)
• 0.8 teaspoon kosher salt divided
• 0.3 cup mirin sweet (Japanese rice wine)
• 1 cup roasted pistachios shelled (preferably Sicilian or Turkish)
• 8  radishes 
• 0.5 cup rice vinegar (not seasoned)
• 3 tablespoons sherry vinegar 
• 0.8 teaspoon shichimi togarashi (Japanese seven-spice blend)
• 1 tablespoon sugar 
• 1 tablespoon butter unsalted
• 5.5 cups water divided

Equipment

• bowl
• frying pan
• sauce pan
• blender
• slotted spoon

Directions

1. Peel artichokes and cut into 1/4-inch-thick sticks, then transfer to a nonreactive heatproof bowl.
2. Bring remaining artichoke ingredients to a boil in a small nonreactive saucepan, stirring until salt has dissolved, then pour over artichokes. Cool to room temperature, keeping vegetables submerged with a small plate.
3. Transfer with liquid to an airtight container and chill, shaking occasionally, at least 1 day.
4. Cook pistachios in 2 cups boiling water in a small saucepan 2 minutes.
5. Drain and transfer to a bowl of ice water to stop cooking.
6. Drain again and peel off skins.
7. Bring mirin, dashi powder, and 3 cups water to a boil in a small saucepan, stirring until powder has dissolved, then add pistachios and simmer, stirring occasionally, until nuts are very tender, about 1 hour.
8. Drain nuts, discarding dashi, then reserve 1/3 cup nuts for garnish. Purée remaining nuts with remaining 1/2 cup water in a blender into a very smooth but thick paste.
9. Trim radishes, then cut each into 6 wedges. Toss with sugar and kosher salt in a bowl until sugar and salt have dissolved.
10. Trim oyster mushrooms, keeping stems intact, then cut lengthwise into 1/4-inch-thick slices.
11. Trim enoki mushrooms, leaving 3 inches of stem, and reserve for garnish.
12. Heat 1 tablespoon oil in a 12-inch heavy nonstick skillet over medium-high heat until hot.
13. Add enough oyster mushrooms to cover skillet in 1 layer, then sprinkle with 1/8 teaspoon kosher salt and 1/8 teaspoon pepper and sauté, turning once, until golden on edges, 2 to 4 minutes.
14. Transfer to a bowl. Sauté remaining oyster mushrooms in 5 or 6 more batches, using 1 tablespoon oil, 1/8 teaspoon kosher salt, and 1/8 teaspoon pepper per batch.
15. When all oyster mushrooms are sautéed, return to skillet, then add butter and garlic and heat, swirling skillet, until butter is melted.
16. Add vinegar and boil, stirring, until evaporated.
17. Remove from heat and discard garlic.
18. Divide pistachio purée among plates, then top with oyster mushrooms.
19. Remove artichokes from container with a slotted spoon and arrange, along with radishes, around oyster mushrooms.
20. Sprinkle with enoki mushrooms, greens, reserved pistachios, and sea salt.
21. ·If using crosnes, halve lengthwise.·Pickled Jerusalem artichokes keep, covered and chilled, 2 weeks. ·Puréed and whole cooked pistachios can be prepared 2 days ahead, then chilled separately, covered. Bring to room temperature before serving.·Radishes can be prepared 4 hours ahead and kept at room temperature.·Mushrooms can be sautéed 2 hours ahead and chilled, uncovered, until cool, then covered. Reheat in skillet, then proceed with recipe.