We have little chefs in our house. Our oldest thinks that overtime someone is cooking she must be in there helping. Everyone loves to cook. I must be a family trait. We learned early on that including our kids in the food prep and cleanup that they seemed more interested in eating the food. So we tried not to discourage them from helping in the kitchen. But when they were little it could be difficult to decide how much they were allowed to help. That was when we decided to let them to small things, like help stir, set the table, take their plate to the kitchen, wash the produce, etc.
How much your kid can help with is really dependent upon their maturity level and skill level. If your kid understands things like sharp objects, cleanliness, and can handle carrying things without dropping them you might decide that they are ready to take on more in the kitchen. It is all relative.
If you aren’t quite sure what your child can handle try letting them try something with supervision. Start small, and build up. Buy some small plastic tools to let them use. We sometimes let our four year old cut things with a small plastic butter knife. But only with supervision and only soft things like berries and bread or dough.
Here is a simple little chart that can help you decide what chores are appropriate for your child. But always take in to account the ability level of your child. And please, always use supervision in the kitchen.