[This is a reply to: http://chowhound.chow.com/topics/7420... on the UK/Ireland board - The Chowhound Team]
We went to the mid-level Christian Constant; if I remember there is a casual cafe, a bistro and and high end steak/seafood restaurant.
And loved Marcus Waering at the Berkely but it was a huge $$ splurge (but as Americans we were underdressed for their 3 course lunch)
But we will return to both again (no regrets).
On Sunday in Paris from what I remember, we might have eaten Lebanese at Noora. I think some of the immigrant/ethnic places are open on Sunday. But I can check my itinerary from last summer and get back to you.
What kind of place are you looking for on Sunday? brunch or dinner?
French or other?