Make the sauce base

• Heat part of the olive oil in a frying pan and soften the onion and bell pepper.
• Add the garlic and tomato paste and cook until fragrant.
• Season with salt, pepper and thyme, then spread the mixture in the bottom of a baking dish.

Slice the vegetables

• Slice the eggplant, zucchini and tomatoes into thin, even rounds.

Arrange the ratatouille

• Layer the vegetable slices alternately over the sauce in the dish, overlapping them in a spiral.
• Drizzle with the remaining olive oil and season with salt and pepper.

Bake

• Cover with parchment paper and bake at 180 °C until the vegetables are tender.