For any place that purports to be a 'breakfast' place, I usually waste my dining dollars on their 'poached eggs'. I say waste because most of the time they are not edible (generally overdone in my estimation) but at least that saves me future bucks because I won't be back there. If Martha Stewart (or anyone) can pre-prepare poached eggs the night before a brunch and not mess them up, then surely a restaurant can also do so - although I don't think poached eggs are that hard to prepare a la minute either if need be.
At any Thai place, my first order is often panang curry. Panang especially can vary so much from restaurant to restaurant and there is a sauce consistency, freshness quality, meat to veg ratio and specific taste (an edge of sweetness but not too sweet) that I prefer. However, I am not sure that serving a panang curry that 'I' like really tests the mettle of 'the chef' in that type of restaurant - it just determines if I will return to try more on the menu another day - when in all likelihood, there will be another 'chef' preparing the meal anyway.
As Anna N pointed out, it depends on the type of restaurant and I would add, ones own personal tastes and expectations, etc.. On the other hand, you said 'the chef' so perhaps this thread is only about haute cuisine establishments where they employ only a single chef/exec of great renown?
I have different expectations of a hamburger or pizza joint than I may have of Alinea or a similar well known restaurant. My 'standards' (as to the taste of any individual dish) may actually be higher for a run of the mill place that specializes in only one type of dish (i.e. hamburgers) than for a highly touted restaurant where I expect my taste buds and expectations to be challenged - perhaps by a tasting menu. Add to that that ambience, service and general flow/overall flavour profile of a meal, and entertainment value can also affect how I 'feel' about value for money at the end of it all - and whether I am likely to return to a very expensive place - but probably don't have much to do in the case of the 'joint' or even mid-level places.
