[Tex/LaTex] Greek in Beamer

Question

How do I get to write Greek in Beamer /without/ using Latin transliterations?
The following did not work.

\documentclass[lualatex]{beamer}
\usepackage[polutonikogreek,british]{babel}
\usepackage{fontspec}
\setmainfont{ebgaramond}

\begin{document}
\title{Not a presentation}

\begin{frame}
  \frametitle{Hullo}
  Hullo, world.
  \textgreek{aisqron}
  \textgreek{καλόν}
  καλόν
\end{frame}
\end{document}

%%% Local Variables:
%%% mode: latex
%%% TeX-master: t
%%% TeX-engine: luatex
%%% End:

aisqron shows, καλόν does not.
I don't know that I need Luatex, but my attempt with standard Latex failed too.

Answer 1

beamer uses a sans serif font, so you must set this font to a font that knows greek:

\documentclass{beamer}
\usepackage[polutonikogreek,british]{babel}
\usepackage{fontspec}
\setsansfont{ebgaramond}
\begin{document}
\title{Not a presentation}

\begin{frame}
  \frametitle{Hullo}
  Hullo, world.
  \textgreek{aisqron} καλόν 
\end{frame}
\end{document}