In a large bowl, mix together the mustard and sugar, then stir in the vinegar and gradually whisk in the vegetable oil and olive oil until they are completely mixed. Stir
in the chives.
Cook the potatoes in a large pan of boiling water for 8-10 mins until just undercooked, then throw in the beans and continue to cook for 4-5 mins until the beans and potatoes are done. Drain the vegetables and toss with most of the dressing.
Heat a dash of olive oil in a large non-stick stick frying pan until very hot and ‘flash fry’ the salmon for a moment until it just changes colour. Pile the beans and potatoes onto plates, lay the salmon on top, then drizzle with a little of the leftover dressing.