In a medium-sized saucepan add a little oil and fry the onion until coated.
Add in a tablespoon of water and the salt and combine.
Cover and leave to soften and sweeten.
Add the flour and butter to the saucepan and stir through the onions.
Continuing to stir cook until it takes on a golden brown hue and smells slightly nutty.
Meanwhile, wash the lentils until the greywater runs clear and drain.
Add the lentils and water to the saucepan and bring to the boil.
Once boiling turn to low and cook for around 20 minutes or until the lentils have softened.
Remove from the heat and blend taking care of any hot splashes.
Place on the hob but do not turn on the heat.
In a bowl whisk together the milk, eggs & lemon juice.
Contşinue to gently whisk the mixture and take one ladle of the soup and slowly pour it into the milk mixture.
Add to now warmed milk mixture to the saucepan and place on the simmer ring. Gently stir and heat the soup until is combined. - Do not boil
Serve the soup in bowls and add the spices.
For red sauce topping:
In small frying or saucepan and fry the butter until it froths, add in the paprika and swirl to combine.