Scalloped Salmon & Sweet Potatoes

Ingredients

• 2 pounds sweet potatoes
• 2 cups low-fat (1%) milk
• 2-1/2 tbsp cornstarch
• 3 green onions, thinly sliced
• 3/4 tsp thyme
• 1/2 tsp salt
• 1/2 tsp black pepper
• 3/4 pound skinned center-cut salmon fillets
• 1/4 cup plain dried bread crumbs
• Large pinch of cayenne pepper
• 1 tbsp unsalted butter, cut into small pieces
• 2 tbsp grated Parmesan cheese