In a bowl, melt butter and mix in Irish whiskey to create a marinade. Submerge the sirloin steaks in this mixture and marinate for at least 3 hours.

Preheat a cast iron pan over medium-high heat. Remove the steaks from the marinade and sear for 3-4 minutes on each side until brown.

Transfer the seared steaks to a baking sheet and bake in a preheated oven at 350°F for about 10 minutes until desired doneness is reached.

In a pot of boiling salted water, add peeled russet potatoes and cook until tender. Mash with cooked kale, seasoning with salt and pepper.

In the same pan, sauté shallots until translucent, then deglaze with whiskey and stir in cream. Simmer until thickened.

Plate the colcannon, place the steak on top, and drizzle with whiskey cream sauce. Serve immediately.