Prepare vegetables by chopping one onion and mincing three cloves of garlic. Slice one red pepper, one yellow pepper, one medium zucchini, and one medium eggplant into bite-sized chunks.

In a large pot, heat two tablespoons of olive oil over medium heat. Add chopped onions and cook for 5-7 minutes until translucent. Incorporate minced garlic and cook for an additional minute.

Add sliced bell peppers and cook for 5 minutes until softened. Introduce zucchini and eggplant, cooking for another 5-7 minutes until vibrant and slightly tender.

Pour in crushed tomatoes and tomato sauce, stirring to combine. Add vegetable broth along with oregano, basil, thyme, and optional red pepper flakes. Season with salt and black pepper, then bring to a simmer.

Lower the heat to maintain a gentle simmer, cover pot, and cook for 30-60 minutes, stirring occasionally. The soup will develop rich flavors and the broth will thicken.

Taste and adjust seasoning as needed. Optionally blend a portion of the soup for creaminess, keeping some chunky. Serve hot garnished with fresh basil.