Preheat oven to 220ºC (200ºC for fan assisted ovens)/Gas M 7
Combine lentils with chorizo and tomato paste. Take each chicken breast and slice them horizontally through the thickest part, open out and flatten with the flat of your hand. Divide the lentil mixture between the breasts and spread over the surface and roll up from widest end.
Roll out pastry to a rectangle approx. 16" x 14" & cut into 4 equal rectangles. Lay each rolled chicken breast on a piece of pastry, brush edges with beaten egg and bring up sides to meet in middle of chicken. Press together firmly to seal, turn over and place on a baking tray.
Make slits in top of each parcel, brush with beaten egg. Bake for 20-25 minutes until pastry risen and golden brown.
Top Tip - Use the pastry trimmings to decorate the tops with leaves or other shapes