Can I substitute canned tomato puree for canned diced tomatoes? I have a soup recipe which calls for diced tomatoes.
If the soup recipe is eventually going to be pureed, then yes, you can substitute with little problem.
If the soup is supposed to be a little chunky, the substitution will change the texture a little, but the flavour will probably remain the same, and all in all it should be fine.
Note that this assumes a can of pureed tomatoes. If what you have is tomato concentrate (it'll be marked as 22 or 28 Bx usually) then you can't substitute directly, as you'd need to dilute.