The MiniPalais in the Grand Palais, technically at 3 Avenue Winston Churchill but more descriptively at the South-East corner of the GP, in the 8th (Metro: Champs-Elysees/Clemenceau), 01.42.56.42.42 is overseen or was designed by Eric Frechon, he of le Bristol and has never disappointed me. Colette had a tour at the Petit Palais given by her primo art historian, Chris Boicos, take a look at his website if you're into art tours, that ended at 13h30 so where to eat neaby was a foregone conclusion. The room is stunning, the outside terrace charming in good weather, and the "menu" very reasonable (29 E).
Our former downstairs' neighbor from 34 numbers up the street and I entered simultaneously so we started off with a lovely Ventoux and two yummy just-right-salted giant cheese brioches. Then she had the "menu" soup of celery with mushroom froth that was ab-fab.
For mains, our guest had the "menu" main, a wonderful rockfish soup with good rouget and squid, Colette had the terrific sandre with a carrot puree and I had a lovely round of sweetbreads wrapped in a comte with a super-wonderful-marvellous potato puree.
We passed on dessert but had a nice bowl of pop-corn (a big trend here now) with caramel with our coffees. Our bill, with said coffees and 1.5 bottle of wine, was 95.66 E a couple.
PS, The MiniPalais gets bonus points for the staff's cross-training and ability to perform services for tables other than their primary ones.