1. Slice potatoes (unpeeled) and sweet potatoes (peeled) thinly and arrange in a large canola-sprayed baking dish.
2. Mix next 5 ingredients and bring to a boil; pour over potatoes.
3. Cover with foil and bake at 400 F for 45 minutes. Blend half & half and cornstarch, pour over potatoes, and tilt the pan back and forth to mix. (Add a little more half & half if necessary.)
4. Return to oven and bake another 20-25 minutes or till lightly browned and bubbly.
