Start by chopping your watermelon into roughly 1-inch cubes, watching as the bright red flesh gives way with a satisfying squish and releases a burst of juice.
Transfer the watermelon cubes into a large mixing bowl, making sure to include all the juicy bits that squirt out.
Crumble the feta cheese using your fingers or a fork, letting it break into irregular, salty pieces, then sprinkle over the watermelon.
Rip or tear the fresh mint leaves into small pieces and scatter them over the salad to add a pop of bright, cooling aroma.
In a small bowl or directly over the salad, pour in the olive oil and squeeze fresh lemon juice using a juicer or your hands, letting the citrusy aroma fill the air.
Sprinkle with freshly cracked black pepper to taste, finishing with a gentle toss to evenly distribute all the ingredients without breaking up the feta too much.
Serve immediately to enjoy the crisp, juicy watermelon contrasted with the salty feta and fresh mint, or chill for up to 2 hours for a more melded flavor.