Recipe: Poppy Seed Chicken Grain Bowls

Name: Recipe: Poppy Seed Chicken Grain Bowls
Ingredients: 1 1/4 cups water; 1 cup brown rice; 1 1/2 teaspoons kosher salt, divided; 2 tablespoons red wine vinegar; 2 tablespoons honey; 1 tablespoon poppy seeds; 1/2 teaspoon ground mustard; 1/2 teaspoon onion powder, divided; 1/4 cup plus 2 tablespoons olive oil, divided; 2 boneless, skinless chicken breasts (about 1 pound total); 1/2 teaspoon freshly ground black pepper; 1/8 teaspoon garlic powder; 1 tablespoon unsalted butter; 2 cups baby spinach (1 1/2 ounces); 1 cup blueberries; 1/2 cup coarsely chopped nuts, such as pecans or almonds