Through curious circumstances, I was gifted with a huge container of sauteed summer squash, green and yellow. I suppose we could just warm it up and eat it, but is there something I could put on it, or something I could make with it? (I didn’t know it was already cooked!) It’s so …bland.
One word - basil!
Both yellow squash and zucchini are wonderful just sauteed with plenty of basil for seasoning. Yum. In fact, I think I’ll have to buy some this week - thanks for the reminder! 
Of course, that’s perfect, thanks! I have a baggie of pesto in the freezer.
Parmesan is good on squash.
Toss it into pasta sauce and serve over penne.
Put spagetti sauce and shredded cheese on top ( Asiago, parm, Mozzarella, etc) Bake long enough for cheese to melt.
good squash needs only butter and pepper.
bake with cheese on top is good (double baked like you can do with mashed potato). could add onions.
Breakfast! It goes great mixed into scrambled eggs with a bit of ham.
Didn’t know it was sauteed. You are halfway there, but you need to remove more water by partially carmelizing each slice by further sauteeing until each slice is as thin as paper. In butter, not olive oil. Add salt, pepper, maybe some Parmesan, and you can hog them all to your self by justifying it as “getting rid of leftovers before they went bad.”
Puree with seasonings and turn it into soup. My favorite zucchini soup is cold zucchini pear, which could easily be adapted to use already-cooked summer squash.
Thank you all for the suggestions. I mixed some up with pesto last night, and the rest is going to get the parmesan treatment, for tonight. There was a lot, but as summer squash is mostly water, it goes down pretty easy.
Rubbish bin comes to mind.