In a large skillet, heat the olive oil over medium-high heat. Season the beef cubes generously with salt and pepper. Working in batches if necessary, sear the beef in the skillet until browned on all sides, approximately 5-7 minutes. Once browned, transfer the beef to the slow cooker.
In the same skillet, add the diced onions and minced garlic. Sauté for about 3-5 minutes, or until the onions become translucent and fragrant.
Add the sautéed onions and garlic to the slow cooker. Layer in the sliced carrots, diced potatoes, and chopped celery on top of the beef.
Pour in the beef broth over the ingredients in the slow cooker. Add the tomato paste, Worcestershire sauce, dried thyme, and dried rosemary. Stir gently to ensure the tomato paste is fully integrated into the broth.
Drop in the bay leaf and taste the mixture, adjusting with additional salt and pepper as desired.
Cover the slow cooker with its lid and set it to low heat for 6-8 hours, or on high heat for 4-5 hours. Cook until the beef is fork-tender and the vegetables are perfectly cooked through.
Once the cooking time is complete, remove the bay leaf from the stew. Taste again and adjust the seasoning if necessary, adding more salt or pepper if desired.
Ladle the beef stew into bowls while it's still steaming hot. Garnish each serving with freshly chopped parsley to add a vibrant touch.
Notes
Pair with crusty bread or serve over creamy mashed potatoes for an extra comforting meal.