For the chutney, wash and clean the tomatoes and, except for something to garnish, cut them into small cubes. Peel onions and finely dice one onion. Bring the tomatoes, diced onion, vinegar, sugar and mustard seeds to the boil in a saucepan and simmer at medium heat for about 10 minutes until everything thickens a little.
Season to taste with salt and pepper. Wash basil, shake dry, pluck leaves from the stalks and chop except for a little to garnish. Stir under the chutney. Cook rice in boiling salted water according to instructions on the packet.
Wash the fish, dab dry and season lightly with salt. Cut the remaining onion into strips. Wash the orange and cut into slices. Put onion strips and orange slices in a pan. Pour on wine, bring to the boil, place salmon slices next to each other on the onion strips and orange slices.
Steam in the closed pan at medium heat for about 10 minutes. Arrange rice, salmon and chutney on plates. Garnish with tomato and basil.