We're in an obesity epidemic and most people don't know how to cook even very basic meals.
Make space for it, squish other classes if you need. Make it mandatory, everyone has to take it. Maybe even ongoing through multiple grades.
Edit: Rice, beans, and even basic meats are cheap. To eat healthy you don't need your meal to be 100% Bell peppers and tomatoes.
Agree it should be taught. It was in my school for half a semester and I still recall much of it. Is a life skill. The other half should be sold financial literacy. Basic accounting.
That being said, it will make near zero difference for obesity. Prepared food is easier and cheaper to access rapidly than at anytime in the past. It is our choice what we eat and the effort we put into it and only itself to blame if we eat poorly. If people wanted to eat healthy, I and sure McDonalds would have more salad options than burger options.