Make the sauce base

• Heat part of the olive oil in a frying pan and soften the onion and garlic.
• Add the diced bell pepper and tomato paste and cook until thickened.
• Season with salt, pepper and thyme.

Slice the vegetables

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

Assemble the dish

• Spread the sauce base in the bottom of a baking dish.
• Arrange the vegetable slices upright in alternating layers over the sauce.
• Drizzle with the remaining olive oil and season with salt, pepper and thyme.

Bake

• Cover with parchment paper and bake until the vegetables are tender.