In a cast iron skillet, heat olive oil over high heat. Add 1 tablespoon butter. When the butter is melted, add the halved loin to the skillet and brown on all sides, about 2 minutes per side. Place the skillet in the preheated oven until a thermometer inserted into the middle of the loin reads 125°F.

Meanwhile, make the herb butter. In a small bowl, mix the butter, parsley, garlic, and parmesan until creamy and light. Place the butter on a piece of plastic wrap or parchment paper and roll it into a log. Remove the herb butter log from the plastic wrap and set to the side while you make the gravy.

Remove the venison to a cutting board. In the same skillet, add flour and continually stir over medium-high heat for about one minute until the flour has cooked and soaked up the drippings left in the skillet. Add a little more oil if there isn’t enough. Add the broth and continue to stir until the clumps of flour have broken up. Allow to simmer until the gravy is the thickness you like. It’s ready when it coats the back of a spoon. Season with salt and pepper to taste.

Slice the venison into about 1-inch slices.

To plate, add about 2 tablespoons of gravy to the bottom of a plate, then add 3 pieces of sliced venison and top each with a thin slice of herb butter. Enjoy it as is, or serve with mashed potatoes, a big Italian salad, and yeast rolls.