Heat the sunflower oil in a medium size cooking pot, add the pork tenderloin and the bunch of rosemary. Brown the tenderloin on both sides and then cook in medium oven for 30 minutes.
For the polenta, boil in a medium size cooking pot the water and the milk. Once it boils pour the cornmeal slowly and stir using a wooden spatula. Let cook for 1 or 2 minutes. Spice with salt, pepper and pour some olive oil. Remove from fire and extend the polenta over a previously sprayed with vegetable oil cooking dish. Let cool.
To serve, cut the polenta in small triangles and brown on both sides on a pan with one tablespoon of natural sunflower oil. In one plate place 2 polenta triangles with one slice of pork accompanied with the cooking juice.