Preheat the oven to 200?C, fan 180?C, gas 6. Cut the sweet potatoes into thick, square-cut chips. Toss with the olive oil, place on a roasting tray and bake for 30 minutes or until crisp.
Meanwhile, cut the salmon into 16 (7cm long) fingers and carefully check for any small bones. Sprinkle the oats onto a plate and roll the salmon fingers in them. Halfway through the cooking of the sweet potatoes, push them to one half of the tray and add the salmon fingers. Continue cooking for the remaining time, along with the potatoes.
While the salmon cooks, boil the tomatoes and garlic in a saucepan for 15 minutes, until reduced and thickened.
Serve the oaty salmon fingers with the chips and a spoonful of the tomato sauce. Allow 5 fingers per adult and 3 per child.