Prepare vegetables: Wash all vegetables and slice them into 1/8-inch thick pieces.
Make the sauce base:
Heat 2 tbsp olive oil in a large, oven-safe skillet.
Sauté 1 diced red onion and 1/2 diced yellow bell pepper until softened.
Add 3 minced garlic cloves and cook until fragrant.
Season with 1/2 tsp salt, 1/4 tsp pepper, 1 tsp dried oregano, and 1 tsp fresh thyme.
Pour in 14 ounces of crushed tomatoes, simmer for 10 minutes, and finish with fresh basil.
Prepare herb dressing: Combine 3 tbsp olive oil, 3 minced garlic cloves, 1 tbsp each of fresh thyme, oregano, and basil, and season with 1/2 tsp salt and 1/4 tsp pepper.
Assemble the ratatouille: Preheat the oven to 390°F (200°C). Arrange the sliced vegetables in a spiral pattern on top of the sauce. Drizzle the herb dressing over the vegetables.
Bake:
Cover the skillet with foil and bake for 40 minutes.
Remove the foil and bake for another 20 minutes until slightly charred and caramelized.
Serve: Garnish with fresh basil and serve with crusty bread or creamy polenta.