I know it's an easy one and there are lots of recipes around, but this was so good . . .
1/4 reasonable sized onion
1 chicken stock cube and some marigold vegetable bouillon powder (I like both the flavours)
salt, pepper, dried mixed herbs
garlic granules or puree
butter or oil or both - you don't need a lot
one medium potato
Cut the top 14 inch off the leek and trim off the outside leaf if it's manky. Don't cut off all the green, it has a great flavour and in a blended soup, it doesn't matter being a bit tough and we want minimal waste. Chop the leek into bits and you might need to rinse them in a colander.
Peel and chop the onion.
Scrub and chop the carrot
Melt the fat/oil in a pan. Throw in the vegetables (not the potato though), mix them well, cover and let them soften on a very low heat for a while, stirring occasionally.
While they are softening, peel the potato and chop in small pieces. Pop into a bowl and cover with water.
When the veg is all soft, add the stock, water (enough to just cover, you can add more later, if you like, seasonings and garlic, bring to a boil, cover and gently simmer for about 20 mins. There's a lot of simmering but it does seem to bring out the flavour.
Then zizz it all using a hand blender or in a blender/processor. Tip the smooth puree back in the pan. It might need slackening with water. Taste and adjust seasoning.
Then add the drained potato. The reason for this is that the vegetables need more zizzing than the potatoes and if you zizz spuds too much, they turn gloopy.
Allow it all to simmer, covered, until the potato is soft, then either mash in in or use a slick blender very briefly.
Check for taste. Add some more stock powder, if you like, adjust any seasoning. Then add some milk (could be cream but this is a frugal blog written by someone on a low fat diet), stir well and reheat to just boiling before serving.
I know it sounds a bit of a palaver but it isn't, a lot of the time you can do something else (read a book, have a G&T, whatever).
And it's even nicer the second day after a reheat!
Oh - and it makes three portions, maybe four, depending on how thick you like your soup.