Melt the butter in a heavy bottomed saucepan. Add the leeks and turn over in the butter. Add a tablespoon of water and season to taste.

Let the leeks sweat for about 5 mins over a medium heat, stirring from time to time, then add the kale. Stir everything around, add another tablespoon of water and cover again. Leave to sweat for a further 10 mins until both vegetables are soft and buttery. You might need to add a little more water half way through.

Meanwhile cook the potatoes in boiling water until just tender while the greens are sweating. Heat the milk, drain the potatoes then gradually add the milk to the potatoes and mash until smooth.

Kids in the Kitchen

Show kids how to peel the potatoes, and get them to add water to the greens pan for sweating, and then to fill the saucepan with cold water for the potatoes. Have them mash the potatoes when they are ready.