On a hot summer’s day when Peter and I were testing bread recipes, we took a lunch break while our doughs were resting between folds. Why not check out some new breads? we thought. We had been on the trail of great rye bread and, up to that point, had found good but not great specimens. But just that morning, a Czech friend, Viera Karpiakova, had told us of a place in Sunset Park, a Brooklyn neighborho