Heat the oil in a large saucepan over a medium heat, then add the onion and bacon. Cook for 8-10 mins until the onion is soft and the bacon is cooked. Stir in the flour, then cook for a further 2 mins.
Pour in the fish stock and bring it up to a gentle simmer. Add the potatoes, cover, then simmer for 8-10 mins until the potatoes are cooked through. Add the cayenne pepper and some salt and pepper then stir in the milk.
Tip the cubed fish into the pan, gently simmer for 4 mins. Add the cream then simmer for 1 min more.
Slice the Penny Loaf vertically into 2 cm slices. Toast for 1 min each side then top with a drizzle of chilli oil and thyme leaves and gently place on the bowls of soup.