I've started having J sit by me at the kitchen counter while cooking dinner. It does two things; includes him in dinner preparations, and gives us good one on one time.
He picks an activity each day to do while sitting at the counter, if he doesn't want to, or there isn't really anything he can do to help.
Thursday night, he wanted to make a "BIG, GIGANTIC Tower!!! for Daddy"
And block by block, he built it... Over.and.over.and.over again.
Each time, knocking it down & restarting with such utter concentration.