Step 1

Preheat oven to 400°. Toss eggplant, zucchini, and 2 tsp. salt in a colander. Let sit 30 minutes, then pat dry with paper towels.

Step 2

Heat ¼ cup oil in a large Dutch oven or other heavy ovenproof pot over medium-high. Add half of eggplant and zucchini and cook, stirring constantly, until vegetables begin to take on color, about 5 minutes. Transfer to a medium bowl. Repeat with ¼ cup oil and remaining eggplant and zucchini.

Step 3

Tie thyme sprigs together with kitchen twine. Heat remaining ¼ cup oil in same pot and cook onion, bell pepper, garlic, and thyme, stirring occasionally, until onion is beginning to brown and is softened, 8–10 minutes. Add half of tomatoes and cook, stirring occasionally, until just beginning to soften, about 5 minutes. Stir in zucchini and eggplant, then top with remaining 1 pint tomatoes (do not stir); season with salt and pepper. Transfer pot to oven and roast until all vegetables are softened and tomatoes have begun to burst, 15–20 minutes.

Step 4

Remove thyme bundle. Transfer to a serving platter and top with basil.