1 - STEP 1 Boil the potatoes for 15 mins or until tender.

2 - Drain, then mash.

3 - STEP 2 Heat the milk and half the butter in the corner of the pan, then beat into the mash, along with the wholegrain mustard.

4 - STEP 3 Gently fry the spring onions in the remaining butter for 2 mins until just soft but still a perky green.

5 - Fold into the mash and serve.