Place the barley in a large saucepan and fill the pot with water. Stir in 1 teaspoon salt and bring to a boil. Reduce the heat to a simmer, and let cook for 45 minutes to 1 hour, or until al dente. Drain, place in a large serving bowl, and set aside to cool.
While the barley cools, make the vinaigrette. Whisk together the orange zest and juice, lemon juice, shallot, olive oil, and kosher salt and pepper.
When the barley is room temperature, add the spinach, walnuts, feta cheese, and cherry tomatoes to the serving bowl. Pour the vinaigrette over the top and toss to combine. Season to taste with additional salt and pepper, and enjoy! Goes great with a high quality piece of seafood.