E., welcome to mamapedia!!
My boys are 11 and 13. They do a wide variety of things in the kitchen and have since they were 5 years old.
They know how to boil water...hard boil eggs...make mac & cheese, grilled cheese sandwiches, soup, buttered noodles, rice, etc.
My oldest knows how to cook bacon and omelets. My 11 year old is working on cooking bacon. He prefers sausage though and will cook that too.
They help with the menu, the shopping for the menu and they are learning timing and planning.
What do you want your kids to learn? the basics? Teach them about kitchen safety...
not to put water in oil
how to stop a fire - should one start
depending upon their ages, they can shred cheese and cut veggies...
never to leave the kitchen when you have food on the stove
how to use the timer on the stove
how to boil water and when to put in eggs, noodles/pasta, etc.
using the blender so they can make their own smoothies...
cutting the fruit for the smoothies...
learning knife safety...how to cut things..
using the peeler - how not to cut themselves with it...
My 13 year old is learning the double boiler so he can have his caramel apples that he likes.