Staff turnover in restaurants is a huge problem, especially within the Chef profession.
Improve conditions - in my experience staff burnout is the top reason for chefs leaving the industry or changing kitchen. Being a chef requires excellent passion which has always been exploited, but now with the massive shortage of talented chefs in the industry, restaurants will not be able to keep a decent chef when they can walk into another position straight away.
Increasing pay will always help, but with razor-thin margins associated with restaurants this is not usually a viable option. The restaurants I work with that have low staff turnover always tend to have similar traits.
1. Gordon Ramsey is a hero of mine but the days of screaming in the kitchen are long gone.
2. Keep a full team; chef vacancies snowball with the added pressure in the kitchen.
3. Thoughtful kitchen layout & well-maintained equipment.
4. Pay for every hour worked, don't expect constant free overtime; there is no quicker way to lose a chef to a temp agency.
5. Tronc - so many chefs have had bad experiences with tronc (not getting anywhere near what was offered), and it is viewed with extreme caution.
6. Splits - try and avoid if possible.
I was a chef for ten years and have been recruiting (permanent only) chefs in London for 5 years. The chefs are out there however not enough to meet the demand. It is a tough job, and you need to show some love if you want to keep good chefs long term.
I hear a lot that the generation of chefs now don't know how to work hard or do their time and work their way up and while this could be the case wishing for how things used to be achieves nothing you have to be proactive in getting a solid team.