Cook off onions in some olive oil until softened, at least 10 mins.
Add garlic, coriander stalks and spices, add a splash more olive oil to keep things sticky, cook for 2 -3 mins more.
Add soaked and drained lentils.
Add water.
Add salt to taste.
Bring to the boil, lid on, reduce heat and simmer until lentils are tender.
Remove from heat, add lemon juice and blend until ¾ blended.
Add big slosh more of good olive oil.
Put soup in bowl and garnish with big spoon of plain yogurt, sumac, chilli flakes, more good olive oil and some of the chopped coriander.
