There are as many recipes for ratatouille as there are French chefs. My cousin, Fred, makes it the best but here is one way to make it. I like to use different colored squashes for effect. I have also done a grilled version where you brush the sliced veggies with olive oil and grill for a few minutes. Then you chop the veggies and add to a bowl with your tomatoes, extra olive oil and seasoning and toss!. It isn’t necessary to peel this vegetable when it is young and tender, so the decision is yours.
Chop an onion and bell pepper, cube an eggplant, 2 zucchini or any other type of summer squash, and 2 tomatoes.
Heat about 3 Tb oil in a large frying pan. Sauté the onion and pepper until fragrant. Add eggplant and squashes and sauté to lightly brown. Season ( this should include at least 2 cloves of minced garlic), cover and cook ~10 mins over medium heat. Add tomatoes and tsp. basil or lots more if it’s fresh, 1/4 tsp. thyme, and 1/4 tsp. oregano. Partly cover and cook another 5 mins or so. Great with Parmesan cheese and toasted bread.