Sear the Beef in Batches
Heat 1 tablespoon of olive oil in a heavy-based pot over high heat. Add the cubed chuck steak in a single layer. Sear without moving for 2 minutes, flip, and brown the other side. Remove the steak chunks and set aside. Drop the heat to medium-high, add the remaining oil, and brown the beef mince, breaking it up completely with a wooden spoon until no pink remains.
Aggressive, small-batch searing initiates the Maillard reaction, developing a complex flavor base and providing the natural deep brown color required for the gravy.
A deep brown crust on the meat pieces and dark caramelized bits stuck to the bottom of the pot.