Sear the Beef: Pat beef cubes thoroughly dry with paper towels and season generously with salt and pepper. Heat 1 tablespoon olive oil in a large heavy Dutch oven or soup pot over medium-high heat. Sear beef in batches for 3 to 4 minutes per side until a deep, dark golden-brown crust forms. Transfer seared beef to a plate and set aside.

Sauté Aromatics & Tomato Paste: Add the remaining olive oil to the pot. Add diced onion, sliced carrots, and celery. Sauté for 4 to 5 minutes until vegetables begin to soften. Stir in minced garlic and tomato paste, cooking for 1 minute until fragrant and the tomato paste darkens to a brick-red hue.

Deglaze the Pot: Pour in 1/2 cup of the beef broth, using a sturdy wooden spoon to vigorously scrape up all the flavorful browned fond stuck to the bottom of the pot.

Add Broth, Barley & Herbs: Return the seared beef and any resting juices back to the pot. Stir in the rinsed pearl barley, remaining beef broth, Worcestershire sauce, dried thyme, and bay leaf. Bring the liquid to a rolling boil over high heat.

Simmer to Perfection: Reduce heat to low, cover the pot with a tight-fitting lid, and simmer gently for 40 to 45 minutes, stirring occasionally, until the beef is fork-tender and the barley is plump and chewy.

Finish & Serve: Stir in the frozen sweet peas during the final 3 minutes of cooking until vibrant green and heated through. Discard the bay leaf. Taste and adjust seasoning with additional salt and pepper if desired. Ladle into warm bowls, garnish with freshly chopped parsley, and serve with warm crusty bread!