- Make the tomato sauce: In a large stock pot, heat olive oil until shimmering. Add shallot and garlic and sweat until shallot is translucent. Add harissa and cook until toasted, then add white wine and sugar and reduce until thickened. Add tomatoes and bay leaves and simmer for 2½ to 3 hours, stirring occasionally to prevent the bottom from sticking and burning.
- Assemble the ratatouille: Preheat oven to 350 degrees. Ladle tomato sauce into a baking pan. Top with slices of zucchini, squash, eggplant, and garlic. Drizzle with olive oil and sprinkle with salt, pepper, and rosemary. Bake for 15 minutes, then sprinkle with crumbled goat cheese.