Ingredients

• 1 leek, white and pale-green parts only, thinly sliced
• Kosher salt
• 1/2 small shallot, finely chopped
• 2 cornichons, finely chopped
• 1/3 cup vegan or regular mayonnaise
• 2 tablespoons Dijon mustard
• 1 tablespoon capers, finely chopped
• 1 tablespoon chopped fresh dill
• 1 tablespoon chopped fresh tarragon
• Freshly ground black pepper
• 2 garlic cloves, finely chopped
• 2 tablespoons plus 1/2 cup olive oil
• 2 8-ounce maitake mushrooms, cleaned, halved through the stem
• Kosher salt, freshly ground pepper

Instructions

1. Cook leek in a small saucepan of boiling salted water until tender, about 4 minutes. Drain; transfer to a colander set in a bowl of ice water. Let cool; drain and transfer to paper towels.
2. Mix shallot, cornichons, mayonnaise, mustard, capers, dill, tarragon, and 3 tablespoons water in a small bowl, adding more water as needed to thin. Fold in leek; season with salt and pepper.
3. For mushrooms: Combine garlic and 2 tablespoons oil in a small bowl. Heat remaining 1/2 cup oil in 2 large skillets over medium-high heat. Season mushrooms with salt and pepper. Cook each, cut side down, in a skillet, pressing to flatten once they begin to soften, until golden and crisp, about 3 minutes per side. Reduce heat to low. Drizzle garlic mixture around mushrooms and cook until garlic is golden, about 1 minute; turn mushrooms to coat. Spoon leek rémoulade onto plates and top with mushrooms.
4. Combine garlic and 2 tablespoons oil in a small bowl. Heat remaining 1/2 cup oil in 2 large skillets over medium-high heat. Season mushrooms with salt and pepper. Cook each, cut side down, in a skillet, pressing to flatten once they begin to soften, until golden and crisp, about 3 minutes per side. Reduce heat to low. Drizzle garlic mixture around mushrooms and cook until garlic is golden, about 1 minute; turn mushrooms to coat.
5. Spoon leek rémoulade onto plates and top with mushrooms.