Rinse the buckwheat under running water, then put it in a pan. Add the water and salt and bring to the boil.
Cook, over low heat, for 15-20 minutes, until no water left in the pan and the buckwheat grains are tender. Turn the heat off, put a lid on and rest for 10 minutes.
Meanwhile, slice the red cabbage, then steam over boiling water for about 5 minutes to soften.
Great the carrot. Drain the beans. Thinly slice the onion.
In a small bowl, mix the oil, vinegar, mustard and garlic. Taste and season to you your liking. Add the dill and set aside.
Fluff the buckwheat with a fork, then transfer to a salad bowl.
Add the onion, beans, grated carrot, steamed cabbage and toss well.
Add the dressing and toss again.
Serve at room temperature.