Lemon-Roasted Potatoes, Chicken and Spinach with Tzatziki

Name: Lemon-Roasted Potatoes, Chicken and Spinach with Tzatziki
Cuisine: European, Mediterranean, Greek
Ingredients: Lemon-Roasted Potatoes and Chicken; 4 sweet potatoes, peeled and cut into ½-inch cubes; Four 4-ounce boneless chicken breasts (skinless or skin on); ¼ cup extra-virgin olive oil, plus more for serving; ¼ cup lemon juice, plus lemon wedges for serving; ½ teaspoon kosher salt; Freshly ground black pepper; 8 cups baby spinach or baby arugula; 1 cup kalamata olives; 2 tablespoons chopped fresh dill; Tzatziki; 1 English cucumber, unpeeled and halved lengthwise; 2 cups strained plain whole-milk yogurt or plain Greek yogurt (see note in directions); ¼ cup finely chopped fresh dill, plus more for serving; ¼ cup finely chopped fresh mint; ½ garlic clove, minced; 1 tablespoon lemon juice; ¼ teaspoon salt