Once the brine is cool, introduce the pork and leave it for about 2 hours.
While the pig is in the brine, blend the garlic, onions, aji panca paste, annatto paste, and cumin, along with grape seed oil.
In a medium bowl, mix the paste with the remaining ingredients, check the seasoning.
After two hours, remove the pork from the brine, put marinate and the pork in a container and leave it overnight, ensuring that all the pork is covered by marinate.
The next morning remove the pork from the container and roll with cling wrap, trying to keep as much marinate as possible within the roll.
In a medium pot, add 4 liters (17 cups) of water and bring it to 60° C/ 140° F . Insert the pork roll in the pot with water for a 25 minute ride, controlling the water temperature remains between 55° and 60° C ( 130-140° F). Remove the pork roll from water and cool it down in a bowl filled with iced water.
Unwrap the pork roll, spread the pork with remaining marinade, and leave it rest for 1 hour. Wash the pork, being careful not to remove all the marinade that covers it.
Cut in thin slices and serve with toasted bread, olive oil, and thin slices of Spanish onion.