Tip the cans of tuna onto a plate and break into chunks. Set aside.
Bash the lemongrass pieces with a rolling pin. Put them into a steamer with the ginger, spring onions, carrot, red pepper, sugar snap peas or mangetout, pak choi and chilli. Steam for 5 minutes.
After 3 minutes, microwave the rice according to pack instructions.
Serve the rice in bowls, topped with the steamed vegetables and tuna chunks.