Preheat the oven to 180°C. To make the stuffing, put all the ingredients in a bowl and mix well. Lay the slices of steak on a board and place a bacon rasher on top of each. Spread a quarter of the stuffing on top of the bacon rasher. Fold the sides in, roll up the steak and tie securely with clean, fine string or strong cotton. Roll them in the flour until evenly coated, then shake off the excess.
Heat the olive oil and butter in a frying pan and fry the beef olives until brown all over. Remove from the pan and put them into an ovenproof dish. Add any remaining flour to the frying pan and stir on low heat until slightly browned. Add the wine, stock, salt and pepper, and bring to the boil, stirring continuously. Pour the sauce over the beef olives and add the bouquet garni.
Cover and cook the beef olives in the centre of the oven for 45 minutes to 1 hour, or until tender. Discard the bouquet garni. Using a slotted spoon, transfer the beef olives to a plate. Remove the string or cotton, return the olives to the sauce and reheat, if necessary.
Garnish with thyme and serve hot with peas tossed in butter, chopped mint and ground black pepper, if desired. The olives can also be made with escalopes of veal or pork.