Method

• 1.
  For the stock, put all the ingredients in a large saucepan with 2 litres (8 cups) water and bring to the boil, skimming off the scum as it rises to the surface. Reduce the heat to medium-low and leave to simmer, uncovered, for 1 hour.
• 2.
  Strain, discarding vegetables but reserving hock. You want 1.5 litres (6 cups) stock in total, so if you have slightly more, return to a clean pan and simmer until reduced to the required amount.
• 3.
  Melt the butter in a large saucepan over medium-low heat, add the onion and cook gently for about 10 minutes or until soft but not browned. Stir in the flour and cook, stirring, for 1 minute. Gradually add stock, then increase heat to medium-high and bring to the boil. Add the peas, return to the boil and simmer over medium-low heat for 3 minutes or until peas are tender.

• 4.
  Meanwhile, skin the ham hock, then remove the meat from the bone and chop into small pieces.
• 5.
  Remove the soup from the heat and leave to cool slightly, then blend with a stick blender until smooth (or in a blender in batches, then return to the pan). Stir in the ham and season with freshly ground black pepper. Warm through over low heat, then serve in warmed soup bowls.