Start by cutting the ribs, slice them right next to the bone separation.
Transfer all this meat to a large baking dish and pour in the milk.
Cover the baking dish with plastic wrap, take it to the fridge and let the meat marinate for 1 hour.
After this indicated time, transfer all the meat to a large pan, cover with water, cover the pan, turn on the heat and let it all cook for 1 hour and 30 minutes.
Meanwhile, cut the onions into 4 pieces and set them aside.
Cut the carrots into smaller pieces and set aside.
Also cut the potatoes into smaller pieces.
Once the meat has cooked through, remove all the pieces from the broth and set them aside.
Now to the same pan filled with the rest of the meat broth add the tomato paste and stir until dissolved. Add the salt, stir and set aside.
Transfer the meat to a baking dish and season with 1 pinch of salt and 1 pinch of black pepper, sprinkle the sweet paprika and the chimichurri, flip and sprinkle the same spices on the other side of the meat.
Add all the vegetables we sliced and pour in the meat broth mixed with the tomato paste.
Season with salt and black pepper to taste.
Take to a preheated oven at 200°C (392°F) and let it roast for 45 minutes.
Serve.