Here is a recipe the kids and I really like.
Carne Asada Venison
Take a 16oz jar of your favorite salsa.
1/2 cup of Brown sugar
1/2 cup of lime juice
1 packet of onion soup mix
Put all the ingredients into a blender and blend till it isn't chunky.
Use half to marinade the venison and reserve the rest. The longer it marinates the more tender it will be. I usually let it marinate for 24 hours.
Two ways to cook:
1) If you grill, grill the meat to medium rare. While the meat is grilling, heat the remaining sauce in a pot. Spoon the warm sauce over the meat when you serve it.
2) Pan fry. Heat a pan over high heat and brown both sides of the venison. Now add the reserved marinade and let the meat simmer until medium rare to medium.