Quickly sear and brown all over a saddle of venison in a large covered pot in graisse. Remove saddle from the heat and cool to the touch. Drain pot of excess fat, but do not disturb the crusty bits on the bottom of the pan.
Stir together a portion of butter and a dollop of prepared mustard. Slather all over roast and roll to coat in finely minced carrot, apple, squash or pumpkin. Sprinkle with freshly cracked pepper.
Place saddle back into large pot, cover and set into the slow coals at the back or side of the fireplace (375ºF oven). Do not remove cover for at least an hour. Begin to check on the doneness of the roast, and baste carefully with any juices that have collected on the bottom of the pot. When the roast has cooked to your desired taste, remove to a platter and keep warm. Degrease the pot and add enough verjus or vinegar to deglaze pot. Push pan juices through a sieve and serve over slices of roast.
The vegetable or fruit coating keeps the roast moist without the addition of barding and adds an indefinable something to the gravy. The amount of butter and mustard may preclude the use of salt, but adjust seasoning to your taste.
Venison available here.