Wild Mushroom And Spinach Lasagna

Ingredients

• 5 pounds fresh spinach, stems removed
• 1 cup (2 sticks) unsalted butter
• 3 cloves garlic, finely sliced
• 1 pound ricotta cheese
• 2 tablespoons coarse salt
• 1 3/4 teaspoons freshly ground black pepper
• 3 pounds wild mushrooms, (chanterelles, oyster, and shiitake), trimmed, cut into 1-inch pieces
• 3/4 cup madeira wine
• 1/2 cup chopped fresh flat-leaf parsley
• 4 1/2 cups milk
• 1/2 cup all-purpose flour
• 1/2 teaspoon ground nutmeg
• 1 cup grated pecorino romano cheese
• 1 one-pound package fresh spinach lasagna sheets