I'm not a pro, but lean meat would need slow cooking- and that's precisely what a cassoulet is. You may want to pay attention to the grain of the meat when you cut it up to minimize stringiness in the texture, but I can't think of anything else. I have never cooked with venison, so I don't know if you have to do anything to mitigate wild flavors before cooking. If you do soak it or marinate it, be sure to pat it really dry if you plan to brown it or th texture will suffer.
Just make sure to rinse of the rock salt and then pat it dry when you cook the venison, otherwise it goes way too salty.
There are many other venison recipes there too. Personally I love to cook with venison as there are so many ways of cooking and presenting the meat. Here in the SW of the UK we do get a lot of it and its a firm favourite with the customers.