Spicy Chicken Eggplant Boats

Name: Spicy Chicken Eggplant Boats
Ingredients: 2 teaspoons dried oregano; 1 1/2 teaspoons kosher salt, plus more as needed; 1 teaspoon ground cumin; 1 teaspoon garlic powder; 1 teaspoon onion powder; 1 large eggplant (about 1 1/2 pounds); 3 tablespoons extra-virgin olive oil; 1/2 yellow onion, diced; 1 tablespoon harissa, or more if desired; 8 ounces ground chicken; One 14.5-ounce can whole peeled or diced tomatoes; 2 tablespoons toasted pine nuts, plus more for garnish; 1/4 cup Greek yogurt; 1 tablespoon chopped fresh dill; Juice of 1 lemon; Freshly ground black pepper; 2 tablespoons chopped fresh mint