3 Halve the melon, remove the seeds, peel and dice.
4 Halve the fennel bulb, remove the core and discard then slice the bulb finely.
5 Whisk the dressing ingredients together and toss with the melon and fennel. Arrange on a platter and place the slices of tuna on top. Add extra mint if desired.
Chef's tip
When searing tuna, get the pan or grill as hot as possible. Cook for 2 minutes on each side - depending on the thickness - then cover and rest for at least 5 minutes before slicing.