In a large casserole pan, begin over a moderate heat and fry the onions, carrot, garlic, bay and rosemary in half the butter until soft and lightly brown. Add the tomato purée and continue cooking for around 10 minutes over a low heat.
Lightly flour the venison pieces with the seasoned flour, turn up the heat in the pan, add the remaining butter and then add the venison, try to get the venison spread out and cook – turning once for around 4 minutes, then add the bones and stir everything round a bit before adding the red wine and cooking for 5 minutes.
Add the mace, then the water, season slightly, bring to a simmer and then reduce the heat. You want this mixture to simmer slowly for around an hour – make sure there is enough water in the pan to just cover everything; if not, add a little boiling water from the kettle to keep things where you want them to be.
Taste the stew and season as required – remove the bones using a stout pair of tongs then pass the mix through a strainer, set over a bowl to remove the solids from the liquids.
Add enough liquid back to the meat to make a nice moist mixture then set the rest aside for serving separately later on. Allow everything to cool a little.