Prepare the Potatoes: Begin by placing your chopped Russet or Yukon Gold potatoes into a large pot. Cover them with cold water, adding a pinch of salt to the mix.

Boil Until Tender: Heat the pot over medium-high, bringing the water to a gentle boil. Cook the potatoes for about 15-20 minutes, or until they are fork-tender.

Drain and Return: Once cooked, carefully drain the potatoes and return them to the pot, allowing some steam to escape.

Sauté the Cabbage: In a skillet, melt 2 tablespoons of unsalted butter over medium heat. Add the shredded green cabbage and sauté for about 5-7 minutes.

Add the Onions: Turn the heat down and stir in the sliced green onions, allowing them to warm through for an additional minute.

Mash the Potatoes: Mash the drained potatoes in the pot until smooth. Incorporate the remaining butter and warmed whole milk.

Combine and Season: Gently fold the sautéed cabbage and green onions into the mashed potatoes. Season generously with salt and black pepper.

Serve Delightfully: Spoon your Colcannon into a serving bowl, creating a small well in the center. Add a pat of butter for finishing touch.