Zest a fresh orange and then juice it for use in the dressing.
Make the dressing in a small bowl by whisking together 1/4 cup orange juice, 1/4 cup balsamic vinegar, 1/4 cup extra virgin olive oil, 1 tablespoon orange zest, 2 teaspoons granulated sugar, 1 teaspoon dijon mustard, and 1/2 teaspoon salt.
Drizzle over salad just before serving. Store in an airtight container in the fridge for up to 4 weeks.