Six Test Kitchen is Arroyo Grande’s flash-in-the-pan new eating establishment heavy on preparation and light on substance.  The basis of this resty is not new–single-seating per night, pricy prix fixe accomodations, an allegedly whiz-bang young gun with  an alleged stellar resume who is–by reduction–basically a local kid cooking in his parent’s–BEAUTIFUL WALL-TO-WALL STAINLESS STEEL–garage.  Everything is ridiculously…