1 can (28 ounces) whole peeled tomatoes
6 tablespoons extra-virgin olive oil
1 large eggplant (1 pound), cut into 1-inch pieces
Coarse salt and ground pepper
2 large yellow onions (1 pound total), diced large
1 head garlic, cloves smashed and peeled
2 bell peppers (any color), seeded and diced large
2-3 zucchini (1 pound total), diced large
1 bay leaf
1 tablespoon fresh marjoram or oregano leaves
2 to 3 tablespoons red-wine vinegar
Step 1: Preheat oven to 350 degrees. Place tomatoes and juices on a rimmed baking sheet and use your hands to break tomatoes into 3/4-inch pieces. Drizzle with 2 tablespoons oil and bake until thickened, 30 minutes, stirring every 10 minutes.
Step 2: Meanwhile, in a colander, toss eggplant with 1 1/2 teaspoons salt. Let sit 20 minutes, then squeeze out excess liquid. In a large Dutch oven or heavy pot, heat 4 tablespoons oil over medium. Add onion and cook, stirring occasionally, until translucent, 5 minutes. Add garlic and cook until onions and garlic are soft, 5 minutes. Add peppers and cook, stirring, until crisp-tender, 4 minutes. Season with salt and pepper.
Step 3: Add tomatoes, eggplant, zucchini, bay leaf, and marjoram to pot. Cook, stirring occasionally, until mixture comes to a simmer. Reduce heat to medium-low, partially cover, and cook at a gentle simmer until vegetables are tender but not mushy, 15 minutes. Season to taste with vinegar, salt, and pepper. Remove bay leaf before serving.