PREHEAT THE OVEN TO 200ºC . In a small bowl, whisk together the olive oil and tomato paste. Add the potato slices, tossing to cover evenly. In an 20 cm ovenproof skillet, layer the potatoes around the outside and in the center. Slide the tomato slices evenly between the sliced potato. Season lightly with salt and pepper, and heat the pan on top of the stove at medium-high heat until crackling noises are heard, about 1.5 minutes. Transfer the pan to the oven to bake until the slices are slightly crisp and the potato is tender when pierced with a knife, about 25 minutes. Remove, sprinkle on the Parmesan cheese and run the dish under the broiler just until the cheese is lightly colored, 1.5 to 2 minutes, watching carefully. Remove and sprinkle on the parsley, and serve.