Stuffing of the timbale:
Sauté the onion in a ½ cup of olive oil until softened. Add the carrot and celery. Next, add the minced meat and brown for 5 minutes. Add the estratto tomato paste with the wine and cook until nearly evaporated. Add 4 cups of the tomato sauce and the peas. Simmer for 1-2 hours on gentle heat, uncovered, stirring occasionally. Season with salt and pepper at the end.
In a separate pan, deep fry the eggplant slices in oil. The eggplant should float on the oil and cook until golden brown on both sides. Drain on a paper towel and set aside to cool. Cook the pasta in a large pot of boiling salted water. Keep it al dente since it will be baked in the oven again. Drain the pasta; season it with the remaining cups of tomato sauce and three tablespoons of parmigiano cheese.
Prepare the spring-form pan (30cm diameter) by coating it with butter and breadcrumbs. Line the pan (base and sides) with a 1-inch thick layer of pasta. Lay the slices of ham on the base of the pasta, then the cheese and the layer of eggplant. Fill with the ragù, leaving enough room for another layer of pasta. Cover with the remaining pasta to seal the top. Sprinkle the top with breadcrumbs and bake for 50 minutes at approximately 350 degrees F.
Once it has cooked, remove the pan from the oven and let it rest for another 10 minutes. Then turn the timbale out onto a serving plate and serve it warm (upside-down).