Wash the pork and dry it. Put it in an oven dish and sprinkle generously with black pepper, cumin, salt and paprika. Rub the meat well and sprinkle with olive oil. Stick the bunches of savory and peeled garlic cloves under it, then leave for a few hours in a cool area to marinate.
Clean the shallot heads of peels and leave them whole.
Wash the yams (batatas), peel and cut them into long strips. Transfer the yams and shallots to the pork in the oven dish, pour in about 4/5 cup (200 ml) cool water, cover with aluminum foil and bake in a preheated 392°F (200 °C) oven for about 2 hours.
Then remove the foil and return the dish to the oven for the pork to gain a nice crisp.
Distribute the meat into serving plates and garnish with the caramelized yams and shallots.