3/4 cup whipping cream
1/4 cup milk
2 bay leaves
1 large spanish onion
1/4 cup butter
3 good sized sweet potatoes
2/3 cup freshly grated parmesan cheese
salt & freshly ground black pepper
In medium saucepan, combine cream, milk & bay leaves. Bring to boil, reduce heat and simmer 10 minutes. Remove bay leaves.
Cut onion in half lengthwise and slice into thin lengthwise strips. Melt butter in large skillet over med-high heat; add onion and cook, stirring often for 15-20 minutes until onion is golden brown. Let cool. Spread 1/4 cup of the cream mixture in generously buttered 12 by 9 shallow baking dish. Arrange layers of sweet potato in dish overlapping slices. Spread with half of the caramelized onions:season with salt and pepper. Repeat layers. Top with layers of sweet potato slices; drizzle with cream mixture, sprinkle with parmesan cheese.
Cover dish with foil. Bake in preheated oven at 350F for 45 minutes. Remove foil and continue to bake 15-20 minutes more until the top is golden brown and potatoes are tender when pierced with a paring knife. Let stand 15 minutes before serving.