%%
%% The LaTeX Companion, 3ed
%%
%% Example 4-1-15 on page I-268 in "Defining the item label (or title) and its design".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{159.0pt}
\sloppy %as the column in the book is so small

%StartShownPreambleCommands
\usepackage{enumitem}
\newlist{steps}{enumerate}{2}
\setlist[steps,1]{label=\arabic{stepsi}.}
\setlist[steps,2]{label=(\alph{stepsii})}
%StopShownPreambleCommands

\begin{document}
Slowly cooked shiitake mushrooms:
\begin{steps}
 \item Soak 20--30 dried mushrooms in hot water
   \begin{steps}
     \item minimum 2 hours
     \item keep water for later
   \end{steps}
 \item Slice shiitake in 5--7\,mm slices
 \item \ldots
\end{steps}
\end{document}
