01 - Pat lamb cubes dry with paper towels and season evenly with salt and pepper.
02 - Heat olive oil in a large Dutch oven over medium-high heat. Brown lamb in batches, turning to sear all sides. Transfer browned lamb to a plate.
03 - Add onion, carrots, and celery to the pot. Sauté for 5 minutes, stirring occasionally until softened. Add garlic and cook for 1 more minute.
04 - Incorporate tomato paste and stir, cooking for 1 minute to develop flavor.
05 - Pour in red wine, scraping browned bits from the bottom. Simmer for 2 minutes to reduce slightly.
06 - Return lamb to the pot. Add potatoes, rosemary, thyme, bay leaves, and stock. Bring mixture to a simmer.
07 - Cover and cook over low heat for 90 minutes, stirring occasionally until lamb is tender and potatoes are cooked through.
08 - If using, stir in peas during the final 5 minutes of cooking.
09 - Remove bay leaves. Adjust seasoning to taste. Serve hot, garnished with fresh herbs if desired.