There are a couple of methods to try depending on the kitchen tools you have available.
Popping your mash into a slow cooker on low can help keep it warm for up to four hours. Before making the transfer, make sure you butter the dish and drizzle some cream on the bottom to keep it moist. Remember to stir at least once an hour.
Heat over a pot
Keeping mash warm for up an hour is easy. Simply, cover your bowl of mash and place it over a pot of simmering water. If your potatoes start to dry out, try adding a little extra butter or milk to adjust the consistency.
How to make perfect mash potatoes
1.25kg waxy potatoes
250g cultured unsalted butter (look for European-style at the supermarket), chopped, at room temperature
2 tsp fine salt
1⁄4 tsp ground white pepper
1⁄2 cup pure cream, hot
Preheat oven to 200°C. Put potatoes on an oven tray and roast for 1 1⁄2 hours or until centres are very tender.
Cut potatoes in half, scoop out flesh, discarding skins, and press through a fine sieve into a large bowl. Beat in butter, salt and pepper. Fold in cream. Serve.