I have visited the Clarendon quite a bit and find the restaurant there, Cafe Tranquillo to be a breath of fresh air every time. Breakfasts at the weekend deserve to be lingered over, with a Bloody Mary or two and some friends, and the menu and staff there make this a delight. May I recommend the chiliquilles highly but be prepared to share them.
The bar is well stocked and the bar staff really know their stuff with a well thought out cocktail menu and local craft beers. Poolside bar service is a huge bonus in the summer months too. Allow a little extra time at weekends as the local crowd is augmented with travelers from the adjoining hotel.
Visit this oasis in the centre of Phoenix and you'll be coming back for more.