In a large stockpot over medium-high heat, heat the oil. Cook a third of the lamb, turning, for 3-4 minutes until browned. Transfer to a plate and repeat with the remaining lamb in 2 more batches, reheating the pan in between.
Sauté the flour, tomato paste, and garlic for 2 minutes. Whisk in the stock and wine off the heat. Add thyme and bay leaves, then bring to a boil. Return lamb to the pan, cover, and simmer for 1 hour and 10 minutes, stirring occasionally.
Combine the potato with the lamb mixture and simmer covered for 30 minutes. Uncover, stir occasionally, and simmer for an additional 10 minutes until the sauce thickens.
Simmer the carrots in a large pot of boiling water for 3-4 minutes until tender. Then, transfer them to a plate. Next, repeat the process with the spring onions and beans.
Combine the carrots, onions, beans, and peas with the lamb mixture, and cook for 2-3 minutes until warmed. Season with salt and pepper to taste. Transfer the flavorful lamb mixture to a large serving dish and enjoy promptly with crusty bread, if desired.