Preheat oven to 400°F. Cut four pieces of aluminum foil into 12-inch sections.
Place all ingredients except the venison in a mixing bowl and mix well. Place both tenderloins on a separate sheet of aluminum foil and add equal amounts of mixture over them.
Put the remaining two pieces of foil over the ingredients and tenderloins, and fold all the edges tightly to seal the ingredients in the foil wrap.
Poke a small hole in the top of each foil packet. Place the foil wrap on a baking sheet and bake in the oven for 25–30 minutes.
Remove from the foil and place the venison on a dish and top with root vegetables.