Whisk together vinegar, oil, garlic, and pepper in a bowl. Scatter half of the rosemary into a shallow dish and place meat on top. Cover the meat in the marinade and rub gently.
Sprinkle remaining rosemary and cover. Refrigerate for at least 30 minutes, turning meat occasionally.
Before cooking, remove meat from refrigerator and let it come to a cool room temperature. Wipe off bits of garlic or rosemary and discard marinade.
Season with salt and pepper; cook as desired.
Prep Time: 5 mins
Cook Time: 30 mins
Total Time: 35 mins