How do I create a table that meets the following specifications?

Question

Following this question: I want to create an environment for a table with the following specifications:

The left column is a vertically centered rotated text, saying Övning. The right column contains paragraphs of text, so I want an empty line for each paragraph (as if I'm using \usepackage[parfill]{parskip}) and \\ to just give me a line break.

The previous question fixed the paragraph issue but broke the centering for the left column. Also, if I use line breaks

Here's my environment now:

\usepackage{array}
\usepackage{rotating}

\newcolumntype{P}[1]{>{%
  \parskip=0.5\baselineskip%
  \advance\parskip by 0pt plus 2pt
   \setlength{\parfillskip}{30pt plus 1fil}}p{#1}}

\newenvironment{exercise}[1]
{
    \begin{tabular}{m{0.05\textwidth}|P{0.85\textwidth}}   # using m in the second column gives back the vertical centering
    \rotatebox{90}{\textbf{Övning}} & \textbf{#1}
}
{\end{tabular}
\bigskip
}

I can use it like so:

\begin{exercise}{5.7}
Övningen finns under Warmup-1 $\rightarrow$ makes10.

Du är given två heltal, \texttt{a} och \texttt{b} som parametrar. Skriv en funktion som returnerar \texttt{True} om ett av talen är 10 eller om summan av dem är 10.

\texttt{makes10(9, 10)} $\rightarrow$ \texttt{True}

\texttt{makes10(9, 9)}  $\rightarrow$ \texttt{False}

\texttt{makes10(1, 9)}  $\rightarrow$ \texttt{True}
\end{exercise}

This produces the following result:

However, if I introduce line breaks, like so:

\texttt{makes10(9, 10)} $\rightarrow$ \texttt{True} \\
\texttt{makes10(9, 9)}  $\rightarrow$ \texttt{False} \\
\texttt{makes10(1, 9)}  $\rightarrow$ \texttt{True} \

Then it breaks my table:

So, I want to be able to use line/paragraph breaks in the right column as usual and I want the text in the vertical column to be centered.

I'm using xelatex with polyglossia (this caused an issue in the previous question).

Answer 1

\\ ends the current row. With \newline instead of \\ it works as expected.

For vertical centering, use an m column also in your own definition:

\newcolumntype{M}[1]{>{%
  \parskip=0.5\baselineskip%
  \advance\parskip by 0pt plus 2pt
   \setlength{\parfillskip}{30pt plus 1fil}}m{#1}}