Based on a uktv recipe.

Ingredients

150 g     Puy lentils
400 ml    Water
  3       Onions
  1 tbsp  Sugar
  2 tbsp  Olive oil

  1 tbsp  Rosemary
  1 tbsp  Thyme
375 g     Puff Pastry

Finely dice onion and fry on low heat with olive oil, after a minute or two add the sugar. Mean while simmer the lentils in water

Finely chop the Rosemary and Thyme, add to the onions. Mix well and keep on a low heat, stir occasionally to stop burning. When onions are soft (about 15 minutes) take off heat and allow to cool.

Mix Lentils and onions then place into a sheet of puff pastry then fold over to create the wellington, pinching ends together.

Place in oven for 20-25 minutes.