You’ll find soya beans in the vegetable
section of the supermarket freezer cabinet.
Put the potatoes in a pan of boiling
water, then boil for 6-8 mins until almost
tender. Add both types of beans, then
cook for a further 5 mins until everything
is cooked. Meanwhile, make the dressing.
Whisk together the harissa and vinegar
in a small bowl with a little seasoning.
Whisk in the oil until the dressing is
thickened. Drain potatoes well, toss with
half of the dressing, then leave to cool.
Flake the tuna, then fold into the
potatoes. Add the remaining dressing.
then gently toss. Divide between 4 bowls
and serve each portion with a handful
of rocket or watercress on top. Serve
warm or cold.