ginger and lime dressing
To make the ginger and lime dressing, place the lime juice, sugar and ginger in a jug and stir to combine. Set aside.
Place the noodles in a bowl and cover with boiling water. Allow to stand for 5 minutes or until tender. Drain and rinse through cold water. Place the noodles, green onion, chervil, chilli and chives in a bowl and toss to coat.
Roll the tuna in the sesame seeds to coat. Heat a non-stick frying pan over high heat. Add the oil and cook the tuna for 30 seconds each side or until just cooked on the outside but still pink in the middle. Slice the tuna, divide between serving plates and serve with the noodle salad and ginger and lime dressing. Serves 4.