Step 1

Place peas with cold water in a pot; leave to soak for 24 to 48 hours.

Step 2

Bring peas to a boil in the soaking water. Reduce heat to low and simmer until peas are very soft, stirring occasionally, about 1 1/2 hours, adding water if needed.

Step 3

Stir butter, salt, sugar, and parsley into peas. For thicker peas, add flour and cook and stir until thick, about 5 minutes.