Preheat oven to 375°F (190°C). In a medium bowl toss the bread cubes with 1 tablespoon olive oil, garlic powder, dried oregano, 1/8 tsp salt, and chopped parsley until evenly coated. Spread in a single layer on a baking sheet lined with parchment.

Bake for 8–12 minutes, stirring once halfway, until golden and crisp. Cool on the sheet; croutons will crisp further as they cool. Set aside.

Balsamic-Basil Vinaigrette

Whisk dressing

In a small bowl or jar combine 2 tablespoons balsamic vinegar, 1 tablespoon fresh lemon juice, 1 teaspoon Dijon, 1 teaspoon honey (if using), minced garlic, 1/4 tsp salt, and 1/4 tsp black pepper. Whisk or shake to blend.

Slowly drizzle in 1/4 cup extra-virgin olive oil while whisking (or add oil to jar and shake vigorously) until the vinaigrette is emulsified. Stir in 2 tablespoons finely chopped basil. Taste and adjust seasoning — add a little more honey if too tart or a pinch more salt if needed.

Salad Assembly

Prepare produce

If not already done, trim and dry the arugula. Cut seedless watermelon into 1-inch cubes and pat lightly with paper towel to remove excess juice. Tear basil and mint leaves into bite-size pieces. Thinly slice chives.

Lightly toss the arugula in a large bowl with about half the vinaigrette (start with 2 tbs). Toss gently so leaves are evenly coated but not wilted.

Add the watermelon cubes, torn basil and mint, sliced chives, and about 3/4 of the croutons to the bowl. Drizzle with another 1–2 teaspoons of vinaigrette if needed and toss very gently to combine. Add more vinaigrette to taste — the goal is bright, lightly dressed components, not soggy fruit.

Transfer the salad to a serving platter or divide among 4 plates. Sprinkle crumbled feta evenly over the top, followed by chopped toasted pistachios and the remaining croutons for crunch.

Season with the remaining 1/2 tsp sea salt and 1 tsp freshly ground black pepper, distributing evenly (you may prefer to salt more sparingly because feta is salty). Serve immediately so croutons stay crisp.