I recently made what I thought was a delicious potato salad in advance of my friend's visit. I boiled some potatoes and mixed them while they were still hot with lemon juice and parsley-basil pesto. I refrigerated them for a few days and then the day of, I tossed the potatoes with some blanched green beans, broccoli and more pesto, lemon and olive oil. Unfortunately the texture of the potatoes ended up getting pretty nasty and cardboard-y and somewhat ruined what was otherwise a delicious lunch. Any suggestions about how to avoid this in the future? Is it just better to cook the potatoes the same day you eat them and never refrigerate?