For pork ragu, preheat oven to 150C. Heat 1 tbsp oil in a non-stick frying pan over medium-high heat, add pork and turn occasionally until browned (2 minutes each side). Transfer to a casserole. Add pancetta to pan, stir over medium heat until fat renders (1-2 minutes), then add onion and garlic and stir occasionally until very tender (20-30 minutes). Deglaze pan with wine and simmer until reduced by half (2-3 minutes). Transfer to casserole with remaining ingredients, cover and braise in oven until pork is meltingly tender (2.5-3 hours). Strain cooking liquid into a saucepan and simmer over medium heat until reduced to 400ml (35-45 minutes). Meanwhile, coarsely shred pork. Season sauce to taste, return pork to sauce and keep warm.
Meanwhile, for potato and eggplant chicche, preheat oven to 200C. Score eggplant halves and roast skin-side down in a roasting pan until very tender (40-50 minutes). Meanwhile, cook potatoes in a large saucepan of boiling water until tender (40-50 minutes) Scoop flesh from eggplant (discard skin) and transfer to a bowl. Peel potatoes, pass through a potato ricer into bowl with eggplant, add egg, stir to combine, then turn onto a work surface. Scatter with flour and bring ingredients just together with your hands to form a soft dough. Roll into a 1 cm-thick log, scattering with a little extra flour if necessary to prevent sticking. Cut into 5mm-thick pieces, then cook in batches in boiling salted water until chicche rise to the surface (2-3 minutes).
Spoon ragu onto a platter. Drain chicche, scatter over ragu, top with Ragusano and serve.