Add the tomatoes, cover the pot with the lid, and simmer until the tomatoes are soft and have released a lot of liquid.
Add the eggplants, zucchini, parsley, basil, thyme, salt and pepper. Stir to combine and then cover with a lid and allow the vegetables to cook until tender (30-40 minutes), stirring occasionally.
When the vegetables are soft, remove the lid and let the ratatouille continue to simmer until the excess liquid has evaporated and the stew is nice and thick. Adjust the salt and pepper to taste and serve with crusty bread.