1. Heat oven to 425 degrees . Coat bottom of a 13 x 9 x 2-inch baking dish with nonstick cooking spray.
2. Place flounder skinned side up on a work surface and season with 1/4 tsp of the salt and 1/8 tsp of the black pepper. Scatter cup of the parsley and 1/2 tsp of the thyme over fish and fold in half. Combine panko with remaining parsley and thyme; spoon evenly over flounder and place in prepared baking dish.
3. Place tomatoes in dish around fish. Season with 1/4 tsp of the salt and remaining 1/8 tsp black pepper. Bake at 425 degrees for 18 minutes or until fish is cooked through and flakes easily.
4. Meanwhile, microwave sweet potatoes on high for 12 minutes or until tender. Cool slightly and scoop flesh into a bowl. Season with remaining 1/4 tsp salt and add cream cheese. Mash until smooth.
5. Serve fish with sweet potatoes. Garnish with chives.