Heat half the oil in a large non-stick frying pan and fry the tuna steaks for 2 minutes per side. Remove 2 of them and cook the last one for 1 minute more on each side (longer for children or if you are pregnant). Set the tuna aside after checking for any bones, cover and keep warm. Clean the pan.
Heat the remaining oil, add the vegetables and stir-fry for 2 minutes. Add the noodles and stir-fry for a further 2 minutes, mixing them right in. Reduce the heat and add the ginger, garlic, orange zest and juice, jam and 50ml water. Stir-fry for 2 more minutes, until well combined and piping hot.
To serve, divide the noodles between bowls and break up the tuna steaks on top. Sprinkle with coriander, if liked.