Cream of Asparagus Soup

This is a good way to use a couple of cheap bunches of asparagus when it's at its best through spring. The soup gets its body from a classic butter-and-flour base rather than from cream alone, so it stays light while still coating the spoon properly.

Simmer the asparagus in stock first and blend it before you build the base. Cooking it separately like this keeps the colour bright and the flavour clean, rather than muddying it by boiling everything together from the start.

Cook the flour in the butter for a minute or two before adding any liquid. This gets rid of the raw, pasty taste that undercooked flour leaves behind and is the difference between a soup that tastes properly finished and one that tastes like it needed another five minutes.

Stir a spoonful of the hot soup into the sour cream before adding it back to the pot, rather than tipping cold sour cream straight in. This brings the two closer in temperature first, which stops the sour cream splitting into little curdled flecks. A squeeze of lemon juice at the end lifts the whole thing and keeps it from tasting flat.