In a small bowl, melt 4 tablespoons of butter and mix in ¼ cup of your favorite Irish whiskey. Pour the marinade over the sirloin steaks, ensuring they are fully submerged. Cover and refrigerate for at least 3 hours, or overnight if possible.

Preheat a cast iron skillet over medium-high heat. Remove the steaks from the marinade, letting the excess drip off, and season generously with salt and pepper. Place the steaks in the hot skillet and sear for 4-5 minutes on each side.

Transfer the skillet to a preheated oven at 350°F and cook for an additional 5-10 minutes to reach desired doneness.

While the steaks are finishing in the oven, peel and chop 2-3 medium potatoes into chunks. Boil them in salted water for 15-20 minutes until fork-tender. In the final minutes, add roughly 2 cups of chopped kale or spinach to the pot. Drain, then mash potatoes and greens together with 2 tablespoons of butter and ½ cup of heavy cream until creamy.

Using the same skillet from the steaks, reduce heat to medium, add chopped shallots, and sauté in residual butter for 2-3 minutes until translucent. Carefully deglaze the pan with ¼ cup of whiskey, scraping the bottom to incorporate all those tasty bits.

Stir in 1 cup of heavy cream, bring it to a gentle simmer, then reduce heat and cook until it thickens, about 5-7 minutes.

Once your steaks are cooked to perfection, remove them from the oven and let them rest for 5 minutes. Plate each steak, generously drizzling the rich whiskey cream sauce over the top. Serve alongside the creamy kale colcannon.