How to Make It
In a medium pot of boiling water, blanch the tomatoes for 30 seconds; drain. Slip off the skins and halve the tomatoes crosswise. Coarsely chop the tomatoes, keeping the juices and seeds.
Preheat the oven to 375°. In a large, deep skillet, heat 2 tablespoons of the oil. Add the garlic and crushed pepper and cook over moderate heat for 1 minute. Add the tomatoes and juices and season lightly with salt. Cook, stirring frequently, until the sauce has thickened, about 25 minutes.
Meanwhile, on a baking sheet, toss the bread with the remaining 1 tablespoon of olive oil. Toast for about 15 minutes, stirring once, until golden.
In 2 separate colanders, toss the zucchini and eggplant with 1 tablespoon of salt each and let drain for 15 minutes. Shake out the excess liquid and pat the slices dry.
Spoon the tomato sauce into a shallow 2 1/2-quart baking dish and scatter the bread cubes on top. On a work surface, top each zucchini slice with a slice of eggplant; blot dry if necessary. Place a strip of roasted pepper and anchovy and a stick of mozzarella at one end of each stack and roll up. Stand the rolls in the baking dish and brush with oil.
Cover with parchment paper. Bake for about 1 hour and 15 minutes, until the vegetables are just tender and the ratatouille is bubbling; remove the parchment halfway through baking. Let rest for 15 minutes before serving.