Cut the hare legs in half at the joint and then cut them once more through the middle of the thigh, so you end up with 3 pieces from each leg.
Put the pieces into a non-reactive bowl or dish, together with the red wine, juniper berries, bay leaf and thyme. Cover with clingfilm and refrigerate for 24-48 hours.
Drain the hare in a colander over a bowl and pat the pieces dry with some kitchen paper.
Season the pieces of hare.
Heat the vegetable oil in a heavy frying pan and fry the pieces, a few at a time, until well-coloured, then put to one side on a plate.
Meanwhile, in a heavy-based saucepan, gently cook the onion in the butter for 3-4 minutes until soft.
Add the tomato purée, then slowly add the red wine and herbs from the marinade, stirring well to avoid lumps forming. Bring to the boil and simmer over a medium heat until the liquid has reduced to half the volume.
Add the beef stock and hare, bring back to the boil, cover and simmer gently for 1 hour (or you can cook this in an oven that has been preheated to 160°C/gas mark 3/ 320° F).
Remove a piece of meat to check if it’s tender; if not, continue cooking for another 30 minutes or so.
Once the meat is tender, remove all the pieces of meat from the sauce and set aside.
Add the blood and continue to simmer the sauce until it has thickened to a gravy-like consistency, then return the pieces of meat to warm through until it’s ready to serve. Adjust the seasoning if necessary.