1.Soak noodles in boiling water in a large heatproof bowl 5 minutes or until softened. Stir to separate strands, then drain.
2.Meanwhile, in a large frying pan, heat reserved tuna oil over moderate heat. Add capsicum and beans; cook and stir 2 minutes or until tender. Add carrot and garlic; cook and stir 1 minute or until tender.
3.Add tuna, noodles, onion, soy sauce and half the sweet chilli sauce to vegetables; cook and toss until to combine. Serve drizzled with remaining sweet chilli sauce.
You can use spaghetti instead of noodles; cooking time will vary.