Complex sentence: The "Hôtel de Ville" had already opened its plentiful stores to the rioters, but they remained unsatisfied: they wanted not just one meal but the assurance that bread would once again be plentiful and cheap.
Split into simpler sentences: The "Hôtel de Ville" had already opened its plentiful stores to the rioters, but they remained unsatisfied. They wanted not just one meal but the assurance that bread would once again be plentiful and cheap.