1. Bring a small saucepan of water to a boil over high heat. Cook pancetta in water 45 seconds, then drain.
2. Heat oil in a large, wide pot over medium heat. Add pancetta and shallots and cook, stirring occasionally, until well browned and crisp, about 10 minutes. Add chestnuts and cook until they start to brown, about 3 minutes more.
3. Add vinegar, frisée, and salt, stirring to coat with oil. Remove from heat and immediately transfer to a serving bowl.
*Find at well-stocked grocery stores.