Hi, dried marrowfat peas are the type you soak, and very tasty too!
For the mushy peas
225g/8oz dried marrowfat peas
1 tsp bicarbonate of soda
35g/1�oz butter
salt
freshly ground black pepper
Soak the peas in a large bowl, in three times their volume of water with the bicarbonate of soda for at least four hours or, if you have the time, overnight.
Drain the peas, rinse under the tap, and place on the stove in a large pan and cover with the water. Cover and bring to the boil and once boiled, reduce the heat and simmer the peas for 1�-2 hours, stirring from time to time.
The peas should be soft and mushy in texture but not too dry. If they are wet, continue cooking over the heat with the lid off to dry out a little. Beat in the butter and season.