For the Balsamic Reduction:
Preheat the oven to 325 degrees Fahrenheit.
- Arrange the bread cubes/strips on a parchment lined baking sheet in a single layer, drizzle with olive oil, and season lightly with salt and pepper.
Bake 12-15 minutes or until lightly golden brown. Set aside to cool.
While the bread cooks, combine the watermelon, basil, mint and feta in a large bowl. Let sit, covered with plastic wrap, for 30 minutes and up to 1 hour in the refrigerator.
- While the watermelon chills, make the balsamic reduction. Combine the balsamic and honey in a small saucepan and bring to a gentle simmer. Cook until the mixture reduced to about 1/4 cup.
Season with salt, transfer to a small glass bowl, and let cool completely.
- Before serving, toss the bread and blueberries with the watermelon in the large bowl. Then, drizzle with the balsamic reduction and toss to combine. Salt and pepper to taste.
- Serve cold.