Step 1: Prepare the watermelon. Ensure the watermelon is well-chilled. Cut the watermelon into uniform 1-inch cubes and place them in a large mixing bowl.
Step 2: Prepare the mint. Wash the fresh mint leaves and pat them completely dry. Chiffonade the mint by stacking a few leaves, rolling them tightly, and slicing thinly, or simply chop them. Add the mint to the bowl with the watermelon.
Step 3: Crumble the feta cheese. If using a block of feta in brine, drain it and crumble it directly over the watermelon and mint. If using pre-crumbled feta, add it to the bowl.
Step 4: Make the lime dressing. In a small separate bowl, whisk together the fresh lime juice, lime zest, and extra virgin olive oil. Season with a pinch of sea salt and freshly ground black pepper. Taste and adjust seasoning as needed to achieve a bright, tangy flavor.
Step 5: Combine the salad. Pour the prepared lime dressing over the watermelon, feta, and mint mixture. Gently toss all the ingredients using a large spoon or spatula until everything is evenly coated. Be careful not to mash the watermelon.
Step 6: Chill and serve. For the best flavor and refreshment, cover the bowl and chill the watermelon salad in the refrigerator for at least 15-30 minutes before serving. This allows the flavors to meld beautifully. Serve immediately after chilling.