Answer:
Soak dry lentils 8hrs in unsalted water, after, remove any irregulars, drain and just cover with heavily salted water, simmer gently until tender (20~30 min.), puree in blender/food processor/food mill, add water to reach consistency as required, season to taste carefully (soup will easily absorb a great deal of seasoning at this point).
For non-vegetarians, simmer soaked lentils in ham stock, omitting salt, adding pieces of cooked ham.
Just before serving, add large dollop sour cream/yoghurt in centre of bowl.
I also enjoy adding Lebanese hot sauce (optional).