Pickled Red Onions

Thinly slice one small red onion and pack it into a jar. Combine 1/2 cup red wine vinegar, 1/2 cup water, 1 teaspoon sugar, and 1 teaspoon salt in a small saucepan and bring just to a simmer. Pour over the onions, let cool, and refrigerate.

For the honey lime vinaigrette:

In a small bowl, whisk together 3 tablespoons fresh lime juice (about 2 limes), 1 tablespoon honey, 1/2 teaspoon Dijon mustard, a pinch of salt, and 3 tablespoons good olive oil. Taste and adjust. If it is too sharp, add a touch more honey. If it is too sweet, a squeeze of lemon juice brightens it right back up.

Arrange the watermelon on a large platter or in a wide bowl. Scatter the arugula over the top. Add the pickled onions and feta. Scatter the mint leaves over everything. Drizzle with the honey lime vinaigrette just before serving, not before, or the arugula will wilt and the watermelon will begin releasing its water into the dressing. Serve immediately.