Bonjour
Here is the explanation of the different meanings of your sentences.
If you say ►
Une entrée avec du riz, du poisson et du sel.
It means your appetizer is rice, fish, and salt.
-
if you say ►
une entée, du riz, du poisson avec du sel
it means you'll have, an appetizer, then rice, fish and salt.
Please, I read you had to list 3 ingredients but salt is kind of weird.
Why don't you relace it by "sauce" .... it would seem more tasty and appetizing.
Hope this helps ☺☺☺