While pastry chef William Werner searches for Tell Tale Preserve Co.'s permanent home, he has become a welcome presence at the Tuesday and Saturday Ferry Plaza farmers' markets, where he brings caramel brownies, confitures du lait, and the astonishing savory muffin he calls the Rebel Within. It's made from the same Parmesan and Asiago cheese batter he uses for his savory cakes, only the Rebel is studded with little nubs of Boccalone breakfast sausage and a whole Glaum Ranch egg, poached so delicately that its yolk oozes like thick hollandaise when you cut into it. How does he keep the egg from overcooking as the muffin bakes around it? A little math, a lot of care, and a fancy oven that can both steam and bake at super low temperatures.