Preheat oven to 200 degree, gas mark 6
Slowly and gently saute onion in the oil until soft. Then add the celery and carrot and cook for 5 minutes.
Add the lentils, tomatoes, stock, and cocoa powder. Bring the mixture to a soft boil, cover and simmer for 50 minutes so that the liquid gets absorbed.
Stir in the aduki beans.
To make the saucse, gently heat the oil with the bay leaf. Remove from the heat and stir in flour to make a paste.
Add the milk slowly, stirring continuously and return it to the heat to thicken.
Stir in the other sauce ingredients and keep stirring to make a creamy sauce consistency. Remove the bay leaf.
When the sauce is completed, place a layer of the lentil mixture into a lasagne dish. Cover with a layer of lasagne sheets, pour over half the sauce and repeat the layers.
Sprinkle the breadcrumb mixture on the top.
Place in the oven and bake for approx 20 - 25 minutes until lightly browned.