I found some interesting buckwheat pasta at the Coop which provided the motivation for this dish.
Make a dressing from minced red onion, salt, mustard, white balsamico, and rapeseed oil and let sit for a bit to mellow the onions. Cut green beans into 2-3cm lengths. Steam until crisp-tender. Cook pasta until al dente, drain and rinse with cold water. Toss the dressing with the beans and pasta and serve at room temp.
We ate this with some good bread and the requisite green salad.