Mix the finely sliced red cabbage and red onion with the grated carrot in a bowl.
Make the dressing by mixing the soy sauce, rapeseed oil, honey and the zest and juice of a lime. Season with salt.
Add half of the dressing to the coleslaw and mix thoroughly.
Season the tuna steaks with salt and pepper, then rub with rapeseed oil. Fry on a very hot pan for 2-3 minutes on each side. Set aside and slice into 3-4 strips.
Fry the tender stem broccoli in the same pan for about 5 minutes, rotating every 1-2 minutes to cook evenly.
To plate, place the coleslaw on a large plate, add the tuna and tender stem broccoli. Finish with the remaining dressing and sprinkle sesame seeds on top.