When my daughters were small we used to have girls helping around the house, students from the local vocational school who were learning to help out in families. Some of them had to learn the simplest things; others were practically running the household at home already. One of the latter was Fadime, a Kurdish girl from Turkey, who taught me to make this plain but delicious lentil soup. It's a Lenten mainstay, easy to make in advance to eat after evening services.
There are hundreds of recipes for Turkish lentil soup, some with many more vegetables, but we like this one best. We tried adding onions once but it wasn't a success.
This amount is enough for five fairly hungry people, but it freezes so well that it's worth making (much) more of.
Wash the lentils and pick out anything that doesn't look like a proper red lentil. Put them in a large pan with two liters of water. Peel and dice the potato, scrape and cut up the carrot and put those in too.
Bring to the boil and cook until you can easily squash a piece of carrot against the side of the pan with a wooden spoon (about half an hour).
Put everything through a sieve or liquidise it in a blender. Add lemon juice, cumin and salt (taste! it probably needs more salt than you thought).
We eat this soup with the spicy sauce on oil days and a mixture of dried mint and paprika flakes on non-oil days, and lots of Turkish bread.
Heat the oil in a small pan. If using butter, melt that in it. Stir in paprika and mint.
Serve in a small bowl to drizzle into the lentil soup.