My Irish grandfather taught me this secret. Just 4 ingredients wrapped in silver pouches for the most flavorful, buttery side you will ever make this March.

This slow cooker 4-ingredient garlic butter red potatoes recipe is inspired by a trick my Irish grandfather swore by every March: tuck simple potatoes, garlic, and butter into little silver pouches so they steam and roast at the same time. The foil keeps the moisture and flavor locked in, giving you incredibly tender, buttery potatoes with concentrated garlicky goodness and just a hint of fresh herbs. It’s a practical, set-it-and-forget-it side dish that feels special enough for a St. Patrick’s Day spread but is easy enough for any busy weeknight.

Serve these garlic butter red potatoes straight from the warm foil pouches, opened up in the slow cooker so everyone can scoop out their own portion. They pair beautifully with corned beef and cabbage, roast chicken, grilled sausages, or a simple pan-seared steak. Add a crisp green salad or steamed green beans to balance the richness, and some crusty bread to swipe up any leftover buttery juices. They also reheat well alongside eggs the next morning for a hearty breakfast hash.

Servings: 6

3 pounds small red potatoes, washed and cut into 1-inch chunks

Prep the potatoes: Wash the red potatoes thoroughly and pat them dry. Cut into roughly 1-inch chunks so they cook evenly and become tender at the same time.

Make the garlic butter: In a small bowl, combine the softened butter pieces, minced garlic, and chopped fresh parsley. Use a fork to mash everything together until the garlic and herbs are evenly distributed throughout the butter.

Form the foil pouches: Tear off large rectangles of heavy-duty aluminum foil, about 12–14 inches long each. You’ll want 4–6 sheets, depending on how full you like each pouch. Lightly crimp the edges up on each sheet to form a shallow tray so the butter doesn’t run off while you’re filling.

Fill the pouches: Divide the potato chunks evenly among the foil sheets, piling them in the center of each. Dot each pile generously with the garlic herb butter, making sure some of the butter touches the bottom and top of the potatoes in each pouch.

Seal the pouches: Bring the long sides of the foil up and over the potatoes and fold them together tightly, then roll up the ends to seal. You want each pouch fully enclosed so the potatoes steam in their own buttery juices and don’t dry out.

Arrange in the slow cooker: Place the sealed foil pouches in a single layer (or slightly overlapping) in the bottom of a large slow cooker. It’s fine if they’re snug; just avoid crushing them so there is still a bit of air space inside each packet.

Cook low and slow: Cover the slow cooker with the lid. Cook on LOW for 4–5 hours, or on HIGH for about 2–3 hours, until the potatoes are very tender when pierced with a fork. Exact timing will depend on your slow cooker and the size of the potato chunks.

Finish and serve: Carefully open one pouch (watch for hot steam) and test a potato cube. If it’s tender and coated in melted garlic butter, the potatoes are done. Turn off the slow cooker. Using tongs, gently open the tops of all the foil pouches and fold the edges back so the potatoes are exposed but still nestled in the foil. Serve directly from the opened pouches in the slow cooker, spooning the buttery potatoes and any pooled garlic butter onto plates.

To lean even more into Irish flavors, swap half of the butter for Irish-style salted butter and reduce any added salt you might normally use at the table. If you prefer a lighter dish, cut the butter back to 3/4 cup and add a splash of low-sodium chicken or vegetable broth to each pouch for extra moisture. For a subtle tang, stir a spoonful of grainy mustard into the garlic butter before dotting it over the potatoes. You can also change up the herb profile: chives or fresh thyme work beautifully in place of, or alongside, parsley. For a cheesy twist, open the pouches during the last 20–30 minutes of cooking and sprinkle the potatoes with grated Parmesan or Irish cheddar, then reseal loosely so it melts. If you’re cooking for a crowd, this recipe scales up easily—just stack the foil packets in two layers in the slow cooker and add 30–45 minutes to the cooking time, checking for tenderness. Leftovers make an excellent base for breakfast hash: pan-fry the potatoes in a skillet until crisp on the edges and top with a fried egg.