Peel the rind of 2 oranges. Divide them into pieces with a sharp knife and remove their slender white zipper. Of the remaining 2 oranges squeeze juice. In a large skillet, heat the oil. Fry previously salted and sprinkled with rosemary fillets until golden. Reduce the heat and pour the orange juice. Simmer for 10 minutes, turning the fillets regularly. Finally, add the pieces of orange and Hold fire another 2 minutes. You can serve with pre-cooked white rice or mashed potatoes.