Easy French Ratatouille

Name: Easy French Ratatouille
Ingredients: 5 tablespoons olive oil, divided, plus more for serving; 1 1/2 pounds eggplant (1 large), large dice; Kosher salt; Freshly ground black pepper; 1 1/2 pounds zucchini or summer squash (3 to 4 medium squash), large dice; 1 medium yellow onion, diced; 2 cloves garlic, minced; 2 sprigs fresh thyme; 1 bay leaf; 1 pound tomatoes (3 to 4 medium), large dice; 1 large bell pepper, large dice; 1/4 cup loosely packed fresh basil leaves, thinly sliced, plus more for serving