My 11 DD loves to cook. I haven't given her free reign in the kitchen, I watch over and she can make most things and knows how to make a pie from scratch
My DS 8 loves to help out with the preparation, but then looses interest very quickly
but my DS 4 he just loves it all. I have a blunt child's knife which he uses to cut soft things like mushrooms etc. He loves to have a go at stirring too at the cooker. He knows what not to touch and I stand behind him. He love the whole process