The "nouvelle Greek" restaurant, Onera, at 222 W. 79th St., has been open for lunch for a couple of months on Tuesdays-Fridays. The only way I found out about it was by accident when searching on Open Table.
Today, my friend and I were alone in the restaurant with glorious air conditioning and enjoyed a terrific 3-course prix fixe (ending with fabulous Greek strained yogurt with honey and blueberries). I particularly enjoyed my octopus salad appetizer ($2 supplement), lemony with slivers of salami, and my swordfish entree was almost as good. My friend's lamb carpaccio with fried shallots and olives was refreshing. I didn't think her "open-face" moussaka (with goat) was up to the level of the other dishes.
All this for $20 per person -- a tremendous bargain. It can be hard to find a table at dinner at Onera, and the same quality food is available with no crowds and a much lower price.