Rub the veal cubes with salt and pepper.

Melt 50 g (2 oz) (4 tablespoons) of the butter with the oil in a large flameproof casserole. Add the onions and garlic and fry until they are soft. Stir in the veal and fry until the cubes are evenly browned. Pour over the wine and stock and stir in the bouquet garni, tomatoes and can juice, the tomato puree (paste) and paprika. Bring to the boil, reduce the heat to low and simmer the mixture for 1 1/2 hours. Add the onions and simmer for a further 30 minutes or until the meat is cooked through.

Meanwhile, melt the remaining butter in a frying-pan. Add the mushrooms and cook for 3 minutes, stirring frequently. Transfer the mushrooms to a warmed serving dish. When the veal is cooked, transfer the cubes and onions to the serving dish. Keep warm while you finish the sauce.

Remove the casserole from the heat and strain the contents into a saucepan, pressing down on the vegetables and flavourings with the back of a wooden spoon. Skim any scum from the surface of the cooking liquid and bring to the boil. Boil for about 10 minutes, or until the liquid has reduced by about a third. Stir in the beurre manie, a little at a time, and cook the sauce for 2 to 3 minutes, stirring constantly, or until it has thickened and is smooth.

Pour the sauce over the meat and vegetables and serve at once.