Place the watermelon in the refrigerator at least 30 minutes before serving so it is well chilled. Cut watermelon into 1-inch cubes (about 4 cups) and transfer to a large bowl. Reserve any small, juice-filled pieces to add just before serving.

Slice cucumber and onion

Thinly slice the cucumber and red onion. If onion is pungent, soak the slices in cold water for 5 minutes, then drain and pat dry to soften the bite.

Trim and lightly fluff arugula. Pick or stack mint leaves and roll them tightly, then slice into fine ribbons (chiffonade). Crumble feta if not pre-crumbled.

Make the dressing

In a small bowl or jar, whisk together the lime juice, white balsamic vinegar, honey, salt and pepper until honey dissolves. Slowly whisk in the extra-virgin olive oil until emulsified. Taste and adjust seasoning: add more salt or lime if needed.

Assemble the salad

Add the arugula, cucumber slices, and most of the mint to the bowl with the chilled watermelon. Pour about two-thirds of the dressing over the salad and toss gently to combine, being careful not to bruise the watermelon.

Scatter the drained red onion slices, crumbled feta, and chopped toasted pistachios over the top. If the salad seems dry, drizzle the remaining dressing sparingly; you want the watermelon to remain refreshing, not soggy.

Finish and serve

Taste and adjust: add a pinch more salt or a squeeze of lime if needed. Sprinkle cracked pink peppercorns or lemon zest and garnish with microgreens or extra mint.

Serve immediately while watermelon is cold. Serves 4 as a side. Leftovers can be kept chilled in an airtight container for up to 8 hours but note the watermelon will release juice and the arugula may wilt.