Here's two cents from a mainly self-taught home cook:
I think jlawrence gives good advice. Focus on skills that can be applied rather than specific, complex recipes.
Learning how to make lasagna teaches you how to make sauce, but will also spend a lot of time teaching you things that are very specific to lasagna. Once you know how to boil lasagna noodles and cover them with seasoned ricotta, all you can really do with that is make lasagna--not particularly useful.
Teach things that can be a basis for improvisation and exploration and be sure to talk about how a simple recipe can be turned in a variety of different directions depending on what's available.
In addition to what jlawrence discusses, I'd consider:
1) Roasting vegetables simply with oil, s & p (an immensely useful skill for a home cook)
2) The sear-and-blast method of cooking meat or poultry and creating a pan sauce by deglazing.
3) Creating improvised soups. If you know the basics here, you'll never go hungry.
4) Making a rice pilaf (which is a base for a lot of exploration and simple, inexpensive meals)
5) Finishing a dish. This is something many people forget and it makes all the difference. Fresh herbs, good olive oil, or a little acid in the right place make the difference between a decent meal and a really good one.
The key is that you should be teaching someone techniques that are useful in a variety of situations that don't require recipes, rather than teaching how to make one specific complex dish. In my mind, a good home cook is someone who can look at the ingredients they have on hand and be able to put together a meal based on tried-and-true techniques without needing to look up a recipe.
Best,
Michael