First (failed) attempt at adding a keyed node. I am using elm-mdl so I thought I could wrap their textfield component in a keyed div but that didn't solve the problem.

new.elm

introField : Model -> Int -> String -> Html Msg
introField model index paragraph =
  node "div" []
    [ ( toString index
      , Textfield.render Mdl [ 3, 0, index ] model.mdl
        [ Textfield.label <|
            "Paragraph " ++
            (toString <| index + 1) ++
            " of Introduction"
        , Textfield.floatingLabel
        , Textfield.textarea
        , Textfield.rows 6
        , Textfield.value paragraph
        , Textfield.onInput <| NewRecipeIntroUpdateParagraph index
        ]
      )
    ]


introFields : Model -> List (Html Msg)
introFields model =
  let
    indexedIntroParagraphs =
      List.indexedMap (,) model.newRecipe.intro

    --x = log "indexed ps" indexedIntroParagraphs
  in
    List.map
      (\p ->
        let
          index =
            fst p

          text =
            snd p
        in
          Lists.li []
            [ Lists.content []
              [ introField model index text
              , deleteIntroParagraphButton model index
              ]
            ]
        )
        indexedIntroParagraphs