Heat a heavy skillet over medium-high heat with 1 tablespoon oil. Season beef cubes with salt and pepper, then sear 2-3 minutes per side until browned. Work in batches to avoid crowding.
2 lbs beef chuck roast
Add diced onion and minced garlic to the crockpot. Place the seared beef cubes on top, then pour in beef broth, tomato paste, Worcestershire sauce, thyme, and bay leaves.
1 large onion, 3 cloves garlic, 2 lbs beef chuck roast, 3 cups beef broth, 2 tbsp tomato paste, 2 tbsp Worcestershire sauce, 2 tsp fresh thyme, 2 bay leaves
Cover and cook on low for 4 hours or on high for 2 hours.
Add the carrots and potatoes to the crockpot and continue cooking on low for another 3-4 hours, until vegetables are fork-tender.
4 medium carrots, 3 medium potatoes
Mix the all-purpose flour with ¼ cup cold water to create a smooth slurry. Stir it into the stew during the last 30 minutes of cooking to thicken the broth.
2 tbsp all-purpose flour
Remove bay leaves, taste and adjust seasoning with salt and pepper, then serve immediately while hot.
2 bay leaves