I remember a couple of years ago watching Jamie Oliver's show. He had an episode where he mentioned that in America, as opposed to some other countries, people tend to keep the knives out of the hands of kids. He said that where he was from they taught them to use them properly. I agreed! I started letting my kids hold the sharp knives and teaching them to cut and chop with them. Of course they need more practice to get the technique down, but they have learned about safety and basic cutting and chopping.
My kids love to help cook, and whenever they ask if they can help I let them do it. Even if dinner is almost done I will find something for them to do, never wanting to turn them away. We have lots of cookbooks in our house and one of them is "Kids Can Cook: Vegetarian Recipes Kitchen-Tested by Kids for Kids." This is a good cookbook. It's all vegetarian recipes that are simple, so that kids can follow them.
We have made recipes out of this book in the past, but my daughter re-discovered it on the shelf this past week. We made the apple walnut salad and the cocoa pudding cake (which was delicious). We took the cocoa pudding cake to a vegan potluck and everyone liked it!
Kids love to cook. I urge you to let them. Get them excited about it. Use it as a learning experience. They will be learning about reading and following directions, measuring, how to clean and prepare food, etc. And then they are also excited about eating it. Here are some pictures of my daughter cooking from this cookbook this week. The very last picture is the breakfast that my daughter made herself one morning - whole wheat toast topped with natural peanut butter and organic jam, served with a pile of strawberries (she made her brother the same breakfast, only she gave him 3 strawberries, while she took 9 for herself).