Over medium heat render the fat from the bacon. Remove bacon pieces and drain on paper towel.
Turn the heat up to medium-high. Mix flour, salt, pepper and ground caraway seeds (if using) and coat the lamb chunks in the mix. Shake of excess and brown the lamb in the bacon fat. Work in batches and then set aside. Reserve 1 tbsp of the seasoned flour.
Lower the heat back to medium and saute the large, diced onion and the minced garlic. Once softened, dust with the reserved seasoned flour and cook for another minute.
Add the Guinness to deglaze the bottom of the pot and use a wooden spatula to scrape off all brown bits. Add the beef stock and bring to simmer.
Add the browned lamb pieces back to the simmering pot, then add the bacon pieces. Cover and simmer on medium-low for 1 1/2 hours.
Add the prepped potatoes, carrots and remaining two onions. Add the thyme and bay leaf. Stir, cover and simmer for another 20-25 minutes or until the veggies are soft.If using frozen peas, add them about 3 minutes before you turn off the heat.
Serve with white bread on the side and garnish generously with parsley. Pair with Guinness or other Irish stout.