Heat one tablespoon of olive oil in a skillet or Dutch oven over medium-high heat. Add the chopped eggplant, reduce heat to medium and cook until it begins to soften and is lightly browned, about 3 to 4 minutes. Transfer to a bowl and set aside.
Add an additional tablespoon of oil to the skillet. When oil is hot, add zucchini and yellow squash and cook until it beings to soften and is lightly browned, about 3 to 4 minutes. Transfer to the bowl with the eggplant.
Add additional oil if needed. Add the chopped onion to the skillet and cook for 4 to 5 minutes or until softened. Adjust the heat as need to prevent the onions from burning.
Add the red bell pepper and continue cooking until they begin to soften, about 3 to 4 minutes. Add the chopped tomatoes and sliced garlic and cook for 2 minutes.
Return the eggplant, zucchini and yellow squash to the skillet. Add in the thyme and Italian parsley, reduce heat to medium-low and simmer uncovered for 20 to 25 minutes or until the vegetables are tender. Remove Italian parsley. Season with salt and pepper to taste. Garnish with additional fresh thyme for a pop of flavor.
For best flavor allow Ratatouille to rest before serving. Serve warm or cold with crusty bread, pasta, or rice.
Notes
Do I Have to Salt the Eggplant?
No you don’t. The old “you must salt eggplant to remove the bitterness” rule isn’t necessarily true anymore with modern eggplants.
Can I Make This Recipe Ahead of Time?
To make ahead or store leftovers: Cool completely then store in the refrigerator, in an airtight container for a day or two. Use within 4 days for best flavor. Reheat over medium-low heat adding vegetable stock or water as needed.
What Other Herbs Can I Use?
A bouquet garni or dried Herbes de Provence (thyme, rosemary, oregano, and basil). When using dried herbs, rub them between your fingers as you sprinkle them into the skillet. This helps to release the flavors that are hidden inside.