Preheat the oven to 350 degrees F.
Pat the sole dry with paper towels and sprinkle with salt and pepper. In a large ovenproof saute pan, brown the sole in 1 tablespoon olive oil on one side, then remove from the pan and set aside. Add the oregano, red pepper flakes and garlic to the pan and saute 1 minute. Next, add the potatoes and chopped tomatoes (with their juices) and cook 1 to 2 minutes. Pour half of the lemon juice into the pan, add the chicken stock and season with salt and pepper. Bring to a simmer, and then add the fish back to the pan and baste with the sauce. Finish cooking in the oven, 5 to 7 minutes.
Remove the fish from the pan and place on a platter. Return the pan to the stove and add the remaining 1 tablespoons olive oil along with the chopped basil and remaining lemon juice. Let the sauce reduce over medium heat, 2 minutes. Serve the fish with the sauce and garnish with chopped basil.