Mix the maple syrup, brown sugar, soy sauce, beef broth, chilli, pepper and garlic to make your cooking liquid. Preheat the oven to 170°C/Fan 150°C/Gas 3.
Put the shoulders into a large casserole dish and pour the broth over venison. Bring it to the boil and transfer to the oven for 3-4 hours, or until the venison meat comes easily off the bone. Once the meat is cooked, drain the liquid, passing it through a mesh strainer and skimming off any fat. Retain the liquid.
Using rubber gloves so that you can do this while the venison meat is still hot, take the meat off the bone and pull the meat into strips.
Now put the bring the rich broth to the boil and reduce it by two thirds. Once reduced, thicken the liquid with cornflour, diluted in a little water. It needs to be thick enough to coat the back of spoon.
For coleslaw, cut the celeriac and gherkins into fine strips. Mix with the lemon juice and mayonnaise. To serve, place the rich game meat in the hot sauce to warm up and serve in toasted brioche buns with a good helping of coleslaw.