Preheat the oven to 350°F | 176℃.
In a large ovenproof skillet, heat 1/2 of the olive oil over medium heat. Add the slices of bread and toast them for about 2 minutes on each side, or until light golden-brown. Remove from skillet and set aside.
In the same skillet, heat the remaining olive oil until shimmering. Add the onion and cook until just translucent, about 5 minutes. Fold in the eggplant, zucchini, red bell pepper, and tomatoes. Continue to cook for an additional 10 minutes, or until vegetables are just tender. Fold in the olives, salt, basil, and thyme. Scoop half of the tomato mixture out into a separate bowl and set aside.
In a medium bowl, whisk together the eggs with the milk, and season with a pinch of salt and pepper.
Lay the slices of toasted bread on top of the tomato mixture in the skillet. Sprinkle with Parmesan. Spoon the other half of the tomato mixture on top of the slices of bread. Pour the egg mixture over the top, and sprinkle the fontina on top of that.
Place the skillet in the oven and bake for 30 to 35 minutes, or until the egg seems set and the top of the strata is golden-brown. Let sit for 10 to 15 minutes to cool a bit before serving.
Portion and serve with apple juice.