Maitake Mushroom Salad with Parmesan and Sourdough Crostini

Ingredients

• 2 heads maitake mushrooms
• 1/4 cup extra virgin olive oil
• 1/2 sourdough baguette cut into ¼-inch thick slices
• 4 cups arugula
• 1 tablespoon lemon juice
• 2 tablespoons Parmesan, grated
• Kosher salt and black pepper, to taste