Preheat the oven to 160°C (approximately 325°F).
For the meatloaf: Soak the bread in a little water. Peel the onion, chop finely and sauté in 2 tablespoons butter. Mix the ground beef in a bowl with the onion, soaked bread, egg, chopped olives and mustard. Knead the mixture well and season with salt and pepper, and form into a loaf. Place the loaf on a parchment-lined baking sheet and bake in the preheated oven for 45 minutes.
For the polenta: Boil the broth, stir in the polenta slowly and the grated Parmesan cheese. Cook while stirring until it thickens. Add the remaining butter and season with salt, pepper and nutmeg. When the meatloaf is done, remove from the oven, coat with the polenta mixture and bake until golden or another 15 minutes.
Rinse the vegetables, peel and cut into slices. Sauté the zucchini, eggplant and onion in hot olive oil for about 4-5 minutes. Add the tomato slices and thyme. Take off the heat, leave until it cools down a bit and season with salt and pepper. Divide vegetables among bowls, top with sliced meatloaf and serve.