Pull the grapefruit apart into segments. Using the tip of a small, sharp knife, loosen the white membrane surrounding each segment and pull it away, trying not to pierce any of the little juice pods. Break up the segments into juice pods and set them aside.
Trim the venison of any tendons or cartilage and slice across the grain into 1/2 inch slices. Place each one between 2 layers of plastic wrap and flatten by pounding with the flat side of a mallet until just over 1/4 inch thick. Season generously with salt and pepper. Preheat an oven to the lowest heat and place a heat proof platter inside.
In a large, heavy skillet heat the olive oil over high heat (you may need to do this in batches). Quickly sear the venison scallops for about 1 minute on each side, then reduce the heat and cook for 1 minute more, until done to your liking (if the venison is cooked beyond the medium rare stage, it will be tough.) Transfer the scallops to the platter in the oven and cover loosely with a piece of aluminum foil.
Wipe the skillet clean and, over medium heat, melt 3 tablespoons of the butter. Add the shallots and cook for 2 to 3 minutes, or until softened. Add the gin and simmer until the pan is almost dry. Add the juniper berries, venison or beef stock, salt, and cracked pepper. Increase the heat to high and simmer until the liquid has reduced by half. Add the remaining pieces of cold butter, remove the pan from the heat, and whisk until the sauce is emulsified. Taste for seasoning and stir in the grapefruit pieces. Place one or 2 venison scallops on each plate and spoon some of the sauce over the top. Serve at once.
c.1997, M.S. Milliken & S. Feniger, all rights reserved