Cooking with the Grinch (Step Into Reading: A Step 1 Book (PB))

My son is a big fan of the Grinch, but he just started reading and he's not able to read it by himself for the moment, so I find this book for him. He read it 2 or 3 times, then he said that it was too easy to read and he complained that the Grinch wasn't grumpy as he should be !