Preparation Sauté salt pork in large skillet over medium heat until golden. Remove with slotted spoon to a 7-quart Dutch oven. Add onion and shallot to skillet and brown quickly over high heat. Add garlic and brown another minute. Transfer with slotted spoon to Dutch oven. Coat beef cubes in seasoned flour, shaking off excess. Add butter to same skillet, as necessary, and brown meat in batches. (Do not overcrowd, or beef will not brown properly). Transfer to Dutch oven as it is browned. Pour Cognac into skillet and reduce by half. Stir in stock and wine and bring to boil, scraping up any browned bits. Stir in Dijon mustard, 1 tbsp of the coarse mustard, and truffle honey, and add to beef in pot. Add reserved pork rind. Bring to simmer, cover partially, and cook until beef is barely tender, about 2-1/2 hours. Add carrots and cook another 10 minutes. Heat 3 tbsp butter in large skillet over medium high heat, add mushrooms and brown well. Add wine and remaining coarse mustard and boil about 30 seconds. Stir mushroom mixture into stew and simmer another 10 minutes. (Can be prepared 1 day ahead. Cover and refrigerate.)