In a bowl, mix together the laverbread and oatmeal until well combined. Season, to taste, with freshly ground white pepper and set aside for 20 minutes.
Melt the butter in a frying pan until foaming, then add the leek and fry for 3-4 minutes, or until softened. Add the picked cockle meat and cook for a further 1-2 minutes, or until heated through.
With damp hands, pinch off pieces of the laverbread mixture and roll into golf ball-sized balls. Flatten the balls slightly to make small patties.
In a separate pan, heat the bacon fat over a medium heat. Fry the laverbread patties, in small batches, for 2-3 minutes on both sides or until golden-brown all over.
To serve, divide the laverbread patties among four serving plates and spoon over the cockles and leeks. Top each serving with two rashers of crisp bacon.