Cut your watermelon into small cubes, around 1-inch or bite-sized pieces. Hollow out the watermelon and use the rind as your salad bowl.
In a big serving bowl (or directly in that watermelon bowl if you're going fancy), add the watermelon cubes, crumbled feta, thinly sliced red onion, and blueberries.
Drizzle the olive oil right over the top. No need for anything fussy, just a good-quality olive oil works wonders here. Gently toss everything together.
Pop the whole thing in the fridge for about 10–15 minutes.
Sprinkle on the chopped mint right before serving. It adds that fresh, herby finish and really brightens up the dish. You can even tuck in a few extra whole mint leaves on top for a little extra wow factor.
