Coulibiac of Salmon

INGREDIENTS

• 2 sheets of thawed puff pastry
• 2 Tb. unsalted butter
• 3 shallots, thinly sliced
• 1 pound mushrooms, sliced
• 1/2 cup white wine
• 1/4 cup chopped dill
• 1 cup cooked (leftover) rice
• 2 6-8 oz. pieces of salmon, cut in half for 4 square-ish pieces
• 1 box chopped frozen spinach, thawed
• 1 egg
• Salt and pepper