Boil the Potatoes: In a large pot, add the russet potato wedges and cover with water. Add a pinch of salt and bring to a boil. Cook until tender, about 15 minutes. Drain the potatoes and return them to the hot pot to let the remaining moisture evaporate.

Cook the Cabbage: While the potatoes are boiling, melt 4 tablespoons of butter in a large skillet over medium-high heat. Once the butter is foaming, add the shredded cabbage, 1 teaspoon of salt, and 1/2 teaspoon of pepper. Cook, stirring frequently, until the cabbage begins to brown, about 5-8 minutes.

Add the Leeks: Stir in the sliced leeks and another 1/2 teaspoon of salt. Continue cooking until the vegetables are tender, roughly 5-8 minutes more. Add the minced garlic and cook for an additional minute. Pour in the half and half, bringing the mixture to a simmer before removing it from heat.

Mash the Potatoes: Add the vegetable mixture to the cooked potatoes. Using a potato masher, combine and mash everything together to your desired consistency. Taste and adjust seasoning with salt and pepper.

Serve It Up: Spoon the mashed mixture into a serving bowl, creating a shallow well in the center. Melt the remaining 2 tablespoons of butter and drizzle it over the potatoes. Finish with snipped chives as a beautiful garnish.