There is so much you can do. Let him use a plastic knife and cut up some fruit for smoothies or fruit salad. My kids 6&9 still enjoy spreading shredded cheese on a torillas. Then pop it under the broiler and they get to see the change. Cucumbers are easy to chop/cut with a plastic knife. Stirring anything is good. Practicing Measuring water at the sink and pour it into a pot to use for pasta. Look for things he can do even if it's not a whole job or even needed. Praise the help even if it's not perfect or messy. This is a wonderful time. Enjoy it it goes by fast. The could be the start of a wonderful thing - cooking together.