Prepare the watermelon: Using a large, sharp knife, slice the watermelon in half crosswise. Then, cut each half into thick slices. Carefully trim away the green rind and any white pith, leaving only the deep red flesh. Cut the flesh into 2.5cm cubes. You should hear a satisfying, clean crunch as the knife passes through. Place the cubes in a large, wide serving bowl.

Slice the red onion: Peel the red onion and slice it into very thin half-rings. As you cut, the sharp, pungent aroma of the onion will fill your kitchen. Place the onion slices in a small bowl and cover with cold water. Let them sit for 5 minutes. This step mellows their bite and leaves them crisp and sweet. Drain well before adding to the salad.

Chiffonade the mint: Stack the mint leaves on top of each other, largest to smallest. Roll them tightly into a cigar shape. Using a sharp knife, slice the roll crosswise into thin ribbons. The moment the knife hits the leaves, a burst of cool, peppery mint fragrance will be released. Set aside a small pinch of the ribbons for garnishing.

Make the dressing: In a small jar or bowl, combine the extra virgin olive oil, red wine vinegar, honey, and lime juice. Add the sea salt flakes and black pepper. Screw the lid on the jar and shake vigorously until the dressing emulsifies, or whisk it in the bowl until it looks slightly thickened and glossy. The smell should be bright and tangy.

Assemble the salad: Add the drained red onion slices and the majority of the mint ribbons to the bowl with the watermelon cubes. Pour the dressing over the top. Using two large spoons, gently fold everything together. Be careful not to break the watermelon chunks; you want them to retain their shape. You'll see the dressing glisten on the melon's surface.

Add the feta: Crumble the block of feta with your fingers or a fork directly over the salad. Aim for a mix of large, creamy chunks and smaller, crumbly bits. The feta should look like snowy white peaks dotted across the red landscape. Gently fold once more to distribute the cheese without mashing it.

Finish and serve: Sprinkle the reserved mint ribbons over the top. If using, scatter the toasted pumpkin seeds and Kalamata olives over the salad. Taste a cube of watermelon with a bit of feta and adjust the salt and pepper if needed. Serve immediately while the watermelon is still cool and the mint is vibrant.