Pat the steaks dry with paper towels and season generously with salt and pepper. In a heavy skillet, heat the oil over medium-high heat until almost smoking. Sear the steaks in the hot oil for 3 minutes per side for medium-rare. Transfer the steaks to a serving plate and let stand.

Using the same skillet, sauté the shallots for 1 minute. Add the red wine, scraping up any browned bits on the bottom of the pan. Let wine boil until reduced by half. Add stock and blackberry preserves, return to a boil and reduce by half. (The sauce should coat the back of a spoon.) Whisk in the 2 tbsp. butter. Season sauce with additional salt and pepper, to taste. To serve, drizzle the sauce over the steaks. Place a pat of compound butter and scatter a few blackberries on the plate.