How to cook
Clean the meat from the skins and fat on its surface. Use a sharp knife, so that you don't ruin the integrity of the tenderloin. Rub it with rosemary, black pepper and very little salt (1 pinch). Drizzle it with most of the olive oil and 3 1/3 tbsp (50 ml) of orange juice and leave it in the fridge for at least 2 hours - the more, the better.
For the sauce - peel and chop the onion, apple and garlic. Heat olive oil over medium heat and fry the onion for 3-4 minutes first with a pinch of salt, add the apple with the spoonfuls of sugar and chopped garlic. Cook, until a light caramel color is obtained and the fruit and vegetables soften.
Pour the mixed orange juice with the wine and cook, until the liquid thickens and almost completely evaporates. Season with a little black pepper and salt, in order to adjust the sweetness of the sauce. Find your favorite taste preference - sweet, sour, savory and emphasize on it by adding more or less salt.
Remove the meat from the refrigerator and leave it for a few minutes at room temperature, so that it becomes more tender during roasting. Meanwhile, strain the sauce and preheat the oven to 390°F (200°C) - upper and lower resistor wire.
Heat a frying pan with the remaining olive oil (a small amount) over high heat and seal the tenderloin on all sides, until it is nicely browned. Do not turn the meat too many times.
Pour the marinade in a baking pan, in which it has been and place it on top. Wrap in aluminum foil and immediately put it in the oven.
Roast the meat for 15 minutes, without removing the foil. Leave it to rest for 5-6 minutes, during which time spread the sauce in a wide plate.
Place the prepared pork tenderloin on it and drizzle it with a little olive oil and coarse flaky salt.
Serve the roasted pork warm and enjoy the incredible contrast of flavors.
Note: If you want the meat to be more pink on the inside, reduce the time in the oven a bit. Keep in mind that even after you take it out, when it is left for 5-6 minutes, it continues to cook.
Enjoy your meal!