Season and coat the beef: Toss the cubed beef chuck with flour, salt and pepper until every piece is lightly coated. This flour layer helps thicken the broth later.
Brown the beef: Heat the oil in a large skillet over medium-high heat. Brown the beef in batches, about 3 minutes per side, until a dark crust forms; avoid crowding the pan.
Transfer beef to crockpot: Move the browned beef into the crockpot. Scrape up any browned bits from the skillet with a splash of broth and pour them in too.
Add vegetables: Layer the onion, garlic, carrots and potatoes over the beef in the crockpot. Tuck in the bay leaves.
Mix the broth: Whisk the beef broth, tomato paste and Worcestershire sauce together in a bowl until smooth. Pour the mixture evenly over the beef and vegetables.
Stir to combine: Give everything one gentle stir so the vegetables settle into the liquid. Make sure the beef is mostly submerged.
Cover and cook on low: Cover the crockpot and cook on low for 8 hours. Resist lifting the lid, since each peek adds extra cook time.
Check for tenderness: At the 8-hour mark, test a piece of beef with a fork; it should pull apart easily. If it resists, cook another 30 minutes on low.
Stir in the peas: Add the frozen peas during the last 15 minutes of cooking so they stay bright green and don't turn soft.
Remove bay leaves and season: Fish out the bay leaves and discard them. Taste the broth and add more salt and pepper as needed.
Ladle and serve: Spoon the stew into bowls, making sure each serving gets a mix of beef, potatoes and carrots. Pair with crusty bread for soaking up the broth.