Mostly sauces and stock. Stuff that takes a long time on the stove.
For example, I'll make a chicken stock (with a whole chicken). When it's done, the cooked chicken gets vacuum sealed and frozen, the stock gets strained and canned. Don't have much freezer space, so the more I can keep on a shelf in a jar, the better. I also jar a lot of tomato sauce. Cooks for hours initially, but if canned stays really good for a year or more.
All of this so I run the stove less in the warmer months. It gets hot enough making bread.