It's not that she was a bad guardian, exactly. Her cooking skills left much to be desired, but according to Max, she was respectable in every other aspect of her duties.
The first time I asked him what he wanted for dinner, Max shrugged and said "I'm good with whatever." He believed his opinion wouldn't be taken into consideration, so he didn't feel like he should contribute to the discussion. Well, I fixed that soon enough. I took an old hat and some pieces of paper. I then wrote down the names of some countries or cities on the paper. France, China, Brazil, Brussels, Athens, Santa Fe, and so forth.
Then I asked Max to pick one paper from the hat, and we would look for a recipe or meal to make for dinner, based on the region he chose. I often asked for his help with cutting veggies, or measuring liquids, etc. From there, it was easy to encourage him to be curious and try new things. I may have created a monster, though, because I wasn't prepared for the escargot he ordered at a brunch place in town.