Cut venison tenderloin into 4 equal pieces, lightly salt and pepper on both sides
Heat oil or fat in high temperature, add meat and fry for about 1 minute each side until brown and pores close
Take filet out of pan and place into pre-heated oven at about 300 degree F
Add red wine, beef broth or venison fond and red wine jelly into pan, heat and reduce liquid to about half.
Cut chocolate into chunks and add tot he sauce, stir constantly until blended.
Take off the heat, place filet on plates and pour sauce over filet