This slow cooker 5-ingredient Irish colcannon is my take on the creamy potato-and-cabbage side dish my Irish grandmother swore by every March. Traditionally, colcannon is a humble Irish classic made with mashed potatoes, greens, and plenty of butter. Here, we let the slow cooker do the heavy lifting so you can go about your busy day and still end up with a big, steamy pot of ultra-creamy, buttery mashed potatoes swirled with tender cabbage and scallions. It’s simple, cozy, and perfect for St. Patrick’s Day or any chilly night when you want the ultimate comfort food without hovering over the stove.
Serve this colcannon right in the slow cooker, with an extra pool of melted butter in the center so everyone can scoop from the edges and drag their spoon through the buttery middle. It’s perfect alongside corned beef, roast chicken, sausages, or a simple pan-seared pork chop. For a meatless spread, pair it with roasted carrots, steamed green beans, or a big green salad. Leftovers reheat beautifully next to eggs for breakfast, tucked into a bowl with sliced sausage, or even used as a cozy base for a ladle of beef or lamb stew.
Slow Cooker 5-Ingredient Irish Colcannon
Servings: 6

Ingredients
3 pounds russet potatoes, peeled and cut into 1 1/2-inch chunks
1 small green cabbage (about 1 1/2 pounds), cored and thinly shredded
1 cup sliced scallions (green onions), divided (about 1 bunch)
1 1/2 sticks (12 tablespoons) unsalted butter, divided
1 1/2 cups whole milk
Directions
Lightly grease the insert of a 4- to 6-quart slow cooker to help prevent sticking and make cleanup easier.
Add the potato chunks to the bottom of the slow cooker in an even layer. Scatter the shredded cabbage evenly over the potatoes, then sprinkle about half of the sliced scallions on top, reserving the rest for finishing.
Cut 8 tablespoons (1 stick) of the butter into pieces and dot it over the cabbage and scallions. Pour the whole milk evenly over everything. Cover the slow cooker with the lid.
Cook on HIGH for 3 to 4 hours or on LOW for 6 to 7 hours, until the potatoes are very tender when pierced with a fork and the cabbage is soft and wilted. The mixture will look a bit separated and brothy at this point, which is exactly what you want for creamy mashing.
Once the potatoes are tender, turn the slow cooker to WARM or OFF. Use a potato masher right in the slow cooker to mash the potatoes, cabbage, and scallions together until mostly smooth with some visible green swirls. If you like a looser mash, splash in a bit more warm milk a tablespoon at a time until it reaches your preferred consistency.
Season generously with salt and freshly ground black pepper to taste, then stir in the remaining sliced scallions, reserving a small handful for garnish if you like. Taste and adjust seasoning again; potatoes can take more salt than you might expect.
Melt the remaining 4 tablespoons of butter in a small saucepan or in the microwave. Use the back of a spoon to create a shallow well in the center of the colcannon, then pour the melted butter into the well so it forms a golden pool. The steam from the hot potatoes will keep it glossy and inviting.
Serve the colcannon straight from the slow cooker, topped with the reserved scallions. Keep it on the WARM setting for up to 2 hours for gatherings, stirring occasionally so the buttery center gets swirled into each serving.
Variations & Tips
For extra richness like my grandmother used to do on special occasions, stir in a splash of heavy cream with the milk or add an extra tablespoon or two of butter at the end. If you prefer a slightly tangy flavor, swap half of the whole milk for buttermilk (just warm it gently before adding so it doesn’t curdle when it hits the hot potatoes). You can also use savoy cabbage or kale instead of regular green cabbage; if using kale, remove the tough stems and chop the leaves finely so they soften fully in the slow cooker. For a slightly lighter version, use 2% milk and cut the butter back to 8 tablespoons total, adding a bit more warm milk if the mash feels too stiff. To turn this into more of a one-bowl meal, fold in cooked, crumbled bacon or diced ham at the end. Leftovers can be cooled, then patted into small patties and pan-fried in a little butter or oil until crisp on both sides—colcannon cakes make a great quick breakfast or side dish the next day. If you’re cooking ahead for a party, you can fully prepare the colcannon, refrigerate it in the slow cooker insert (if your model allows), then reheat on LOW with a splash of milk, stirring occasionally and adding the final pool of melted butter just before serving.