Directions
1. Preheat the oven to 375 degrees. Scatter the peppers and zucchini in a single layer on a baking tray, drizzle with three tablespoons of olive oil, season with salt and pepper. Roast until the vegetables are softened, about 15 minutes. You may need to do this in two batches.
2. Cut the top off the loaf to create a lid. Hollow out the loaf by scooping out the soft bread, leaving an edge of around an inch on the top and bottom, so the top and bottom aren’t too thin.
3. Place half of the removed inner bread into a food processor or blender and pulse to make breadcrumbs.
4. Mix the remaining oil with the sherry vinegar and garlic. Add any juices from the roasting tin to the mixture.
5. Take the hollowed out loaf and spread the pesto over the base. Begin layering the vegetables, drizzling with the oil and vinegar mixture. Add basil leaves and breadcrumbs between the layers, repeating until the loaf is full. Put the lid on, wrap tightly with foil or plastic wrap, place in the refrigerator overnight.
6. Pack a bread knife and cutting board and slice just before serving.