Ratatouille with Red Snapper

Name: Ratatouille with Red Snapper
Ingredients: 3 tablespoons olive oil, divided; 1 large eggplant (about 1 pound), trimmed and cut into small dice (about 3 cups); 1 medium onion, cut into small dice (about 1 1/2 cups); 2 cloves minced garlic (about 2 teaspoons); 2 medium zucchini (1 pound total), trimmed, cut into small dice (about 2 1/2 cups); 1 (14.5-ounce) can no-salt-added diced tomatoes; 1 teaspoon herbs de Provence (or 1/2 teaspoon dried thyme and 1/4 teaspoon each dried rosemary and dried marjoram); 3/4 teaspoon salt, plus more for seasoning; 1/2 teaspoon freshly ground black pepper; 1/4 cup chopped fresh basil leaves, plus more for garnish; 4 (5-ounce) fillets red snapper, skin on; 2 teaspoons lemon juice; 2 teaspoons rosemary (or other herb) infused olive oil, optional