Follow the packet instructions for soaking the dried marrowfat peas over night, rinse and drain.
In a large pan add the olive oil and soften the diced onion and carrot.
add the curry powder, pepper and salt mix in well.
add the peas, stockcube and top up with hot water covering the peas by a good inch or so. Mix in well and bring to the boil for a minute.
Turn down to a low simmer and cook out for a good few hours, stir occasionally until soft, thick and mushy.
add the knob of butter and mix in well, then remove from the heat and allow to fully cool.
Using premade (shop bought, pre rolled for total ease) puff pastry place about 2-3 tablespoons of the cold mix in a sausage shape down one side of a 4x4 inch square of pastry, roll up into a sausage shape (stick the edge with some beaten egg mix if you need to).
Brush the finished rolls with beaten egg and bake in the oven until golden (follow packet instructions, should be about 180-200C for about 15-30 minutes depending on oven).