Once a hunter kills a deer, he begins processing the meat immediately to keep it from spoiling. Hunters often keep the venison heart to cook because it is very flavourful. Once you remove the sections of the heart not meant for consumption, you will have meat that you can cook easily in a skillet.
Place the venison heart under cold water. Remove as much blood as possible from the heart. Push on the heart to pump out any blood stored in the chambers and arteries. Once the water runs clear, place the venison heart in a bowl of cold water.
Soak the venison water in cold water for 30 minutes. Place the bowl in the refrigerator while the heart soaks.
Remove the heart from the bowl and dry it. Use a sharp knife to loosen and cut the membrane off of the heart. The membrane is slippery, so be careful while you remove it.
Cut off the valves and ventricles at the top of the heart, along with the fat, and discard. Starting at the pointed end of the heart, slice the meat off in rounds and place them off to the side. Trim off any excess fat and discard the thin upper heart chambers.
Cut the rounds of meat into small 1- to 1-½-inch pieces. Place the pieces into a zipper-seal plastic bag and cover them in Worcestershire sauce or your preferred marinade. Let marinate for an hour in the refrigerator.
Place a skillet over medium-high heat. Add 2 tbsp of butter to the skillet. Chop up an onion and two cloves of garlic to sauté in the pan with the venison heart meat.
Add the cut deer heart pieces to the skillet along with the chopped onion and garlic. Cook the deer heart for 5 to 10 minutes until the liquid runs clear and the meat no longer appears dark red or pink.