Set your oven to 190C. While it's heating, place a heavy, lidded casserole dish over medium heat, add the butter and fry the bacon until lightly crisp. Remove from the dish. Fry the sausages until browned, remove and cut into 5cm pieces.  

Remove the dish from the heat and lay the onions in a layer over the bottom of the dish. Follow this with alternate layers of potato, sausage pieces and bacon. Scatter with the thyme sprigs and half the parsley. Pour in the chicken stock and milk and cover with the lid. Bake in the oven for 90 minutes. Allow to cool slightly, then season with salt if necessary. Grind black pepper over the top and scatter with the reserved parsley, then serve.

Adam's tip: I avoid adding extra ingredients to recipes where they aren't traditionally used, but those who want a more substantial meal could add cabbage or carrots to the coddle. 

Looking for more ideas for St Patrick's Day? Try Adam Liaw's Irish tea cake.