• Wash and dry the eggplants. Cut a small lid off the top of each one and scoop out the inner pulp without breaking the outer shells.
• Put the pulp in a strainer, sprinkle it with salt, and let it drain to take out the bitterness.

Make the filling

• Soak the stale bread in a little milk.
• Finely chop the onion, one garlic clove, and a small handful of parsley.
• Soften them in the butter with the crumbled bouillon cube.
• In a large bowl combine the ground veal, the sausage meat, the softened onion mixture, the Parmigiano Reggiano, two eggs, the soaked bread squeezed of its milk, salt, nutmeg, and a little chopped parsley.
• Knead by hand until the filling is even.
• Fill the four eggplant shells with the meat mixture, put their lids back on, and set them in a baking dish.
• Drizzle with olive oil and bake at 375°F (190°C) for close to one hour, covering the dish with aluminum foil after the first 30 minutes.

Make the topping

• Sauté a handful of chopped parsley and the second garlic clove in three or four tablespoons of olive oil.
• Add the reserved eggplant pulp, washed, squeezed and chopped, then season with salt and cook it gently.
• Hard-boil the remaining egg, let it cool, peel it, and chop it finely.

Assemble

• Take the baked eggplants out of the oven and let them cool completely.
• Remove the lids and slice each eggplant in half lengthwise.
• Blend the cooked pulp with the yogurt on medium speed for two minutes until you have a smooth cream, then chill it.
• Stir a little finely chopped parsley into the chilled eggplant and yogurt cream.
• Spread a generous layer over the cut surface of each eggplant half, scatter the chopped hard-boiled egg on top, and finish each one with a parsley leaf.
• Keep them in the refrigerator until you serve them.