Preheat oven to 400 degrees F.
Season the steaks generously with salt and pepper on both sides. Heat 2 teaspoons oil in a large oven-safe skillet over medium high heat. Add the steaks to the pan and sear 2-3 minutes until a golden crust forms. Turn the steaks over and and cook another minute, then transfer the skillet to the oven. Cook until steaks are desired doneness, about 6-10 minutes for medium rare depending on the thickness of the steaks. Carefully remove the skillet from the oven and place the steaks on a plate. Cover with foil to keep them warm while you make the sauce.
Heat the skillet on the stove over medium heat and add the remaining teaspoon of oil. Add the shallots and garlic and cook 30 seconds until shallots start to soften. Add the pomegranate juice and stock and turn the heat up to high. Simmer until the sauce is reduced by half and slightly thickened, a few minutes. Lower the heat and whisk in the mustard and butter. Season the sauce to taste with salt and pepper. Remove the garlic clove.
Serve the steaks with the pomegranate Dijon sauce drizzled on top. Garnish with pomegranate seeds, if desired.