Peel the aubergines, peppers and one of the onions. Dice them, as well as the courgettes but keeping their skin on.
Peel the tomatoes, keeping the skins and insides and then cut them into small cubes. Put them in a colander for 10 minutes mixed with salt to drain.
Crush the four garlic cloves in their skin.
Sweat the aubergines, peppers, courgette and onion separately, each time with olive oil and garlic. Meanwhile, chop the green and purple basil and set aside, keeping the stems and branches.
Combine the cooked vegetables, diced tomatoes and basil, and put in the fridge.
Brown the tomatoes, including the skins in olive oil with the basil branches, the second white onion and a pinch of sugar. Then, gently cook in the oven for 30 minutes at 130-140°C.
Once cooked, drain the vegetables and save the syrup. Put in the fridge.
Mix the flour and sparkling water and then brush the zucchini flowers with the mixture. Plunger them into the cooking oil at 170°C for one minute on each side. Once fried, place the flower fritters onto kitchen roll. Season with salt and pepper and set aside.
Place the thin ratatouille on a plate. Decorate with a courgette flower and the basil leaves. Serve chilled with a drizzle of the tomato syrup.