We peel the apples, remove the seeds and cut the meat into small cubes. Peel and finely chop the onion. Heat a little extra virgin olive oil in a frying pan and poach the apple along with the onion for about 10 minutes.
Meanwhile we chop the walnuts and one of the rosemary branches. Add to the poached apple and onion. Sauté another 10 minutes or until the mixture is slightly caramelized. Then we salt and pepper, remove from heat and let cool before using to fill.
With a very sharp knife, we open the pork loin lengthwise, in book form. We spread it on the work table and season to taste. We place the filling along one end of the loin and roll it on itself, making sure it is centered.
We flange with twine thread, that is, we tie it lengthwise and width so that do not open during cooking in the oven or the filling comes out. Heat a little extra virgin olive oil in a frying pan and, over high heat, brown the meat roll on all sides.
We place the meat in a baking dish, add the wine and the rest of the rosemary branches. Season again and cover with butter, diced or gobbled. We introduce the dish in the oven, preheated to 180 ° C with heat up and down, and roast for 45 minutes. We remove the source from the oven and remove the twine.
Strain the liquid and heat it in a pan, along with the fine cornmeal. We remove until thickened and let’s get a sauce. We serve the sliced meat with the sauce to wash it down and, if we have leftover stuffing, we also take it to the table.