Tuna and dragon fruit salad

A long, long time ago, I made a tuna and dragonfruit salad, using a white dragonfruit.  Recently, I found a red dragonfruit:

For those who, like me, are not familiar with the dragonfruit, they are the fruit of a certain variety of cactus, and are also known as pitayas.  The flesh can be red or white, and is studded with little edible black seeds.  The insides look glorious, like Aladdin's Cave:

This time, when I made the salad, as well as substituting red dragonfruit for white, I used ordinary sandwich tuna (instead of tuna slcies), and added the sliced almonds in the original recipe.  I don't recommend the sandwich tuna substitution unless it's all you have, because it makes for a mushier salad, and is not as visually attractive.  However, flavourwise, it is a lovely salad, with a passionfruit and mustard marinade for the tuna and a vinegarette salad dressing.

If you have never tried dragonfruit before, this salad is a lovely way to use it, and makes for a quick and easy weekend lunch.