Boil the lasagne and set aside.
Heat pot over a medium flame. And add the seasoned minced beef. Make sure meat is well done. Add roucou or tomato paste.
Make the White Sauce: (approx 15 mins) Over a low flame, melt the butter, stir in the flour, and add the milk and black pepper. Mix, preferably with a fork to ensure that the flour don't lump together. Continue to boil until the milk gets thick. Remove immediately from the flame.
Put a layer of meat; then cheese then add the lasagna. Add a layer of white sauce and continue in the same manner. On the top layer add some more grated cheese.
On the top layer add some more grated cheese.
Bake for 40 minutes at 250 degrees F. Allow to cool before serving