pancetta or bacon, diced • large onion, finely diced • shallots, chopped • unsalted butter • + kilogram (2.5 lbs) beef chuck, in 1-inch cubes • all-purpose flour • Kosher salt and black pepper • Cognac • beef stock • Dijon mustard • Pommery mustard or other whole-grain Dijon mustard • large carrots, peeled and cut into half-moon slices •