I have the Sneaky Chef books too and the secret is to start very small in the amount of pureed veggies or fruits or beans you are sneaking in, like 1/4 cup pureed cauliflower in your home made mac and cheese, then work your way up slowly to 3/4 cup. I have a little boy who I can fool with some things but he's so picky he can taste it and he makes me frustrated.