\documentclass{article}
\usepackage{minted}
\setminted{linenos,frame=single}
\begin{document}
Without \verb|escapeinside|:
\begin{minted}{c}
LINE
\end{minted}
With \verb|escapeinside|:
\begin{minted}[escapeinside=||]{c}
LINE
\end{minted}
\end{document}