Cook eggs in boiling water for 8 minutes. Then cool in cold water, peel and cut in half lengthways.
Peel and dice the onion. Heat the butter in a saucepan and sauté the onion until translucent. Dust with flour and sweat, but do not let it brown. Pour in the vegetable stock and stir vigorously. Add the crème fraiche and simmer for 5 minutes and season with salt, pepper and mustard.
Cook rice in salted water according to the instructions on the packet.
In the meantime, add the egg halves to the sauce and heat them up. Rinse the dill and shake dry. Pluck the tips off, chop and stir into the sauce.
Arrange the rice with mustard eggs on plates and serve garnished with dill.