Brown the beef: In a large pot or Dutch oven, heat the olive oil over medium-high heat. Season the beef with salt and pepper, then brown the beef in batches, making sure each piece gets a nice sear on all sides. This will take about 5-7 minutes per batch. Remove the beef and set it aside.

1. Sauté the vegetables: In the same pot, add the chopped onion, garlic, carrots, and celery. Cook for about 5-7 minutes, stirring occasionally, until the vegetables soften and the onions become translucent.
2. Add the barley and broth: Stir in the rinsed barley, then pour in the beef broth and water. Add the bay leaf, thyme, and rosemary. Bring the mixture to a simmer.
3. Simmer the stew: Once the stew is simmering, reduce the heat to low. Cover the pot and cook for 1.5 to 2 hours, or until the beef is tender and the barley is cooked through. Stir occasionally and check the liquid level—if it looks like it’s getting too thick, add a little more water or broth.
4. Add the potatoes and peas: After the beef is tender and the barley is cooked, add the diced potatoes to the stew and cook for another 15-20 minutes, or until the potatoes are tender. If using frozen peas, stir them in during the last 5 minutes of cooking.
5. Finish and serve: Remove the bay leaf, taste the stew, and adjust seasoning with more salt and pepper if needed. Serve hot, garnished with fresh parsley.