To start, top and tail the vegetables to remove any roots and hard bits. Then, slice the yellow squash, green squash, and eggplants on a mandolin. You can also get them thinly sliced by hand.
Next, bring a pot of water to a rolling boil. Make a small X incision at the bottom of each tomato. Then, place the tomatoes in the boiling water for 10-15 seconds.
Remove the tomatoes from the boiling water and place them in a bowl filled with ice and water. Allow them to cool completely.
Once they are cooled, peel their skin off and discard it. Keep the peeled tomatoes aside on a chopping board.
Then, using a knife, make 2 two tomatoes thinly sliced. They won't slice on a mandolin because they are too soft and juicy. The remaining six tomatoes can be diced.
Make the sauce
To start, heat some olive oil in a pot over medium heat. Then, add the onions and garlic and allow them to saute for about 5 minutes. Or until the onions become translucent.
Then, add the roasted diced bell peppers and the diced peeled tomatoes.
Add your seasoning ingredients including salt, pepper, thyme, parsley, and basil.
Give the mixture a good stir and allow them to cook for 5-8 minutes.
Remove them from the heat and blend the ingredients until they are smooth.
Set the blended sauce aside and allow it to cool completely.
Assemble the ratatouille
Preheat your oven to 360ºF (180ºC).
To start, spread a generous layer of sauce on the bottom of your baking dish.
Then, layer the thinly sliced vegetables in a circle starting from outer edge with the eggplant, then tomato, yellow squash, and finally green squash concentrically towards the center. Only create one layer of thinly sliced vegetables.
Finally, drizzle the vegetables with some olive oil and season salt, pepper, and chopped fresh rosemary.
Top the baking dish with a piece of parchment paper that fits perfectly inside to cover vegetables.
Bake and finish off the ratatouille
Bake in the preheated oven for about 60 minutes.
Once baked, remove the dish from the oven and take off the parchment paper sheet.
Place a ring mold on the plate of your choice. Then, add a spoonful of ratatouille vegetables and place it inside.
Keep stacking vegetables until the ring is completely filled. Wipe away any juices that run out underneath the ring.
Carefully remove the ring and clean up any juices flowing out.
Finally, combine some of your leftover baked sauce with olive oil. Use it to garnish the plate. Finish off your dish with fresh parsley and a few sprigs of chives.
Serve with dollops of mascarpone cheese or toasted bread.