1. Prepare the Meatballs: In a large bowl, combine the ground beef, ground lamb, breadcrumbs, parsley, Parmesan, egg, garlic, salt, and pepper. Mix well until all the ingredients are evenly incorporated. Shape the mixture into small, bite-sized meatballs.

2. Brown the Meatballs: Heat the olive oil in a large pot or Dutch oven over medium heat. Add the meatballs and brown them on all sides, about 2-3 minutes per side. Once browned, remove the meatballs from the pot and set them aside.

3. Sauté the Vegetables: In the same pot, add the diced onion, sliced carrots, and diced potatoes. Sauté the vegetables for 5-6 minutes, or until they begin to soften.

4. Add Broth and Seasonings: Stir in the tomato paste, dried thyme, dried rosemary, and beef broth. Bring the mixture to a simmer.

5. Simmer the Stew: Return the browned meatballs to the pot, cover, and let the stew simmer for 30-35 minutes, or until the potatoes are tender and the meatballs are cooked through.

6. Finish with Peas: In the final 5 minutes of simmering, stir in the frozen peas to allow them to warm through.

7. Serve and Enjoy: Ladle the Irish Meatball Stew into bowls and savor the comforting flavors of this timeless Irish classic. Pair it with a crusty loaf of bread for a truly satisfying meal.