How to make a Cuban style roast pork in five easy steps. Mix 1 cup naranja agria (sour orange), 1/2 teaspoon cumin, 1 teaspoon dried oregano, 4 tablespoon crushed garlic, salt and pepper, and olive oil in a bowl. Place 1 small boneless pork loin roast in a re-sealable plastic bag. Pour marinate into the bag and refrigerate over night. Place the marinated pork loin roast in a baking dish and cover tightly with aluminum foil. Bake at 325 degrees for 1 to 1 1/2 hours. Remove foil in the last 15 minutes of cooking time. Sauté a large onion (sliced) and serve.