1. Cook the chopped bacon in a large heavy pot over medium heat until crisp and the fat has rendered, then use a slotted spoon to transfer the bacon to a plate and leave the fat in the pot.

2. Pat the lamb chunks dry with paper towels, then toss them with the flour, salt, and pepper until evenly coated.

3. Brown the lamb in batches in the hot bacon fat over medium high heat, adding a little olive oil as needed, turning the pieces until all sides are well caramelised, then transfer the browned lamb to the plate with the bacon.

4. Reduce the heat to medium, add the diced onion and sliced celery to the pot, and cook while stirring and scraping up any browned bits until the vegetables are softened and lightly golden.

5. Stir in the minced garlic and tomato paste and cook for 1 to 2 minutes, letting the tomato paste darken slightly and become fragrant.

6. Pour in the red wine to deglaze the pot, scraping the bottom with a wooden spoon, and let it simmer for 2 to 3 minutes until reduced by about half.

7. Add the stock, bay leaves, and thyme to the pot, then return the browned lamb and cooked bacon along with any accumulated juices, and bring the mixture just up to a gentle boil.

8. Reduce the heat to low, cover the pot partially with a lid, and let the stew simmer for about 30 minutes so the lamb begins to tenderise.

9. Stir in the potato chunks and carrot pieces, making sure they are mostly submerged in the broth, then continue to simmer gently for 45 to 60 minutes, stirring occasionally, until the lamb is very tender and the vegetables are cooked through.

10. Skim off any excess fat from the surface of the stew, taste, and adjust the seasoning with additional salt and pepper as needed.

11. Stir in the lemon juice if using and the chopped fresh parsley, then let the stew rest for 5 minutes to settle before serving.

12. Ladle the lamb stew into warm bowls, garnish with extra parsley, and serve hot with crusty bread or your favourite sides.