Cut the salmon and pineapple cubes. Red onion cut into 4 pieces and separate the individual from them. In a bowl and mix the soy sauce, vinegar, sugar, grated onion, garlic and the oil. Marinate cut fish for about 1-2 hours and then strung on skewers, alternately salmon, pineapple and red onion. Tampering with pepper and bake on the BBQ or in an oily lightly frying pan. Can be served with sauce optional and taste.