Season the steak generously with salt and pepper on both sides. Let it rest at room temperature for about 15 minutes.

Heat a cast iron skillet over high heat for about 5 minutes. Add oil, then lay the steak in, searing for 3-4 minutes.

Transfer the skillet to a preheated oven at 400°F and bake for another 10-15 minutes.

Remove the skillet from the oven, transfer the steak to a plate, add Irish whiskey to the skillet, and simmer for about 5 minutes.

Peel and chop potatoes, boil in salted water for about 15 minutes until fork-tender, then drain and mash with butter, cream, and green onions.

Serve the creamy colcannon mash topped with the rested steak and drizzle the whiskey sauce over it.