Classic Ratatouille

Name: Classic Ratatouille
Ingredients: 5 Tbsp. extra-virgin olive oil, divided; 1 large yellow onion, thinly sliced; 2 garlic cloves, finely chopped or grated; 1 large globe eggplant (about ¾ lb.), cut into ½ pieces; 1 zucchini, quartered lengthwise and thinly sliced; 1 red bell pepper, seeded and chopped; 1 pint cherry or grape tomatoes (about 12 oz.), halved or quartered if large; ¼ tsp. dried oregano, crumbled; ¼ tsp. dried thyme, crumbled; ⅛ tsp. ground coriander; ¼ tsp. fennel seeds; ¾ tsp. Diamond Crystal or ¼ tsp. plus ⅛ tsp. Morton kosher salt; Freshly ground black pepper; ½ cup torn fresh basil leaves