Ohh ... do not worry man! You will definitely get penalized or so just because of word count under 300. After all you are having original and authentic content, so do not worry at all.
It is true that in order to rank higher, the higher word count is important, but in your case I understand that adding unnecessary words just to inflate the word count won't help, instead it might spoil the user experience.
My clear suggestion here is you make some UI improvements here so that the page will look longer to the reader and they will spend more time on the page.
- For example add more images of the recipe in making
- Add video in the beginning of the article.
- Is it possible to add any quiz to the page? It will make it interactive and fun for the readers and will reduce the bounce rate.
- At the end of the recipe add a "Submit Your Version of this Recipe" wherein users will submit their photos of the recipe.
This way the page will become more interactive, users stay time will increase and bounce rate will decrease.
Good news is that, Google notices all this and will put your rankings at the top.
All the best!