split stem on adjacent notes in a chord

For a piano score I want to include a chord that has two notes like the c and the c-sharp.
Tried <c! cis>, but lilypond puts both the natural and the sharp sign before the chord.

I have seen a score where one stem goes halfway, then splits, making room for the b on the left part of the fork and the b-flat on the right fork. (notes might change)

How would this be done in lilypond version 2.26.0?

Attached an example, but don't know if the attachment is visible for you[2026-06-22 13 19 05.jpg]

Thanks, Erik