Step 1

Place potatoes and parsnips in a large pot, cover with water and bring to a boil over high heat.

Step 2

Reduce heat and simmer until tender, 20 to 25 minutes.

Step 3

Drain well, return to pot, add milk and butter and mash until almost smooth (or leave slightly chunky, if you prefer).

Step 4

Season with salt and pepper and serve.