Heat 100 g (3½ oz) clarified fat in a shallow pan, add 2½ kg (4 lb 10 oz) breast, uncovered cutlets, neck and shoulder of mutton all cut in pieces of approximately 90 g (3 oz) in weight. Fry quickly until well coloured, having added 12 g (⅓ oz) salt, milled pepper and 5 g (⅙ oz) caster sugar. The sugar will settle slowly to the bottom of the pan where it will caramelize, then dissolve when the liquid is added thus giving the required colour to the sauce. When well coloured, drain off almost all the fat, sprinkle with 60 g (2 oz) flour and cook together for a few minutes. Moisten with 1½ litres (2⅝ pt or 6½ U.S. cups) water or stock and add 500 g (1 lb 2 oz) chopped fresh tomatoes or 1½ dl (5 fl oz or ⅝ U.S. cup) tomato purée, 1 clove of crushed garlic and a large Bouquet garni.
Bring to the boil whilst stirring, cover with a lid and cook in the oven for 1 hour.
Transfer the pieces of meat to a clean pan, add 20 button onions coloured in butter and 30 potatoes trimmed to the size and shape of Pommes à l’Anglaise. Skim off the fat from the sauce and strain over the ingredients, cover with a tight fitting lid and place in the oven to continue cooking for a further 1 hour.
Skim off any remaining fat and place the Navarin in a deep dish or timbale.