01 - Pat beef pieces dry and season evenly with salt and pepper.
02 - Heat a splash of oil in a large Dutch oven over medium-high heat. Brown beef pieces on all sides, then remove and set aside.
03 - Add onions, carrots, and celery to the pot. Cook for 5 to 6 minutes until softened. Stir in garlic and cook 1 additional minute.
04 - Stir in tomato paste and cook for 2 minutes to deepen flavor.
05 - Return beef to pot, pour in red wine, and scrape browned bits from the bottom. Simmer for 3 minutes.
06 - Pour in beef stock, add bay leaves and thyme. Bring to a boil, reduce heat to low, cover, and simmer for 1.5 hours.
07 - Add potatoes, cover, and simmer for 45 minutes until beef is tender and potatoes are cooked through.
08 - Stir in cornstarch mixture if desired, simmer for 5 minutes until the stew thickens.
09 - Remove bay leaves, adjust salt and pepper to taste, and serve hot.