Trim the backstrap and cut it into bite-sized chunks. Season with salt and freshly ground pepper.
Trim the backstrap and cut it into bite-sized cubes.
Heat the olive oil in a cast-iron pan over medium-high heat. Once the oil starts to shimmer and let off tiny wisps of smoke, add half of the backstrap cubes in a single layer. Take care not to overcrowd the pan, leaving plenty of space between each piece of meat. Cook the backstrap in three batches instead of two, if necessary.
Sear the backstrap to a medium-rare in a hot cast-iron skillet.
Cook the bites for 4 to 5 minutes, flipping often to brown all surfaces evenly. Season well with freshly cracked black pepper. Remove the first batch to a warm platter and cover loosely with foil while you repeat the process with the remaining backstrap.
Once all the venison has cooked, reduce the heat to medium and add the butter and garlic to the pan, stirring constantly to prevent burning the garlic. Once the butter has browned a bit, return the meat to the pan and toss well to coat with the garlic butter sauce.
Serve as a main course or on skewers as an easy appetizer.
Sprinkle with finely chopped fresh parsley just before serving, if desired.