- Heat oil in a large saucepan. Add rashers rind bacon, diced onion and diced 2 stalks celery and cook over a medium heat for 10 minutes to soften onion.
- Sprinkle flour over mixture and stir to combine without lumps. Stir in the water over heat until mixture boils and thickens. Stir in the milk.
- Add cubed waxed potato and bay leaf and simmer for 10 minutes to cook potatoes. Remove bay leaf.
- Add drained tuna, corn and chopped parsley and simmer for 5 minutes to heat through. Season with salt and pepper to taste.