Preparation Arrange half of russet potatoes in 8x8x2-inch glass baking dish. Season with salt and pepper. Sprinkle 1/4 of rosemary over. Top with half of sweet potatoes. Season with salt and pepper. Sprinkle 1/4 of rosemary over. Repeat layering with remaining russets and sweet potatoes, seasoning each layer with salt, pepper and 1/4 of rosemary. Pour cream over. Cover tightly with plastic wrap and microwave on High until potatoes are tender, about 18 minutes. Sprinkle both cheeses over potatoes. Microwave uncovered on high until cheeses melt and bubble, about 3 minutes. Cool 10 minutes.
Preparation Arrange half of russet potatoes in 8x8x2-inch glass baking dish. Season with salt and pepper. Sprinkle 1/4 of rosemary over. Top with half of sweet potatoes. Season with salt and pepper. Sprinkle 1/4 of rosemary over. Repeat layering with remaining russets and sweet potatoes, seasoning each layer with salt, pepper and 1/4 of rosemary. Pour cream over. Cover tightly with plastic wrap and microwave on High until potatoes are tender, about 18 minutes. Sprinkle both cheeses over potatoes. Microwave uncovered on high until cheeses melt and bubble, about 3 minutes. Cool 10 minutes.