Mix the starter ingredients together until smooth, cover, and let rest at room temperature overnight.
Combine all of the dough ingredients and mix and knead them together -- by hand, mixer or bread machine, until you've made a soft, somewhat smooth dough; it should be cohesive, but the surface should still be a bit rough. Allow the dough to rise, covered, for 3 hours, gently deflating it and turning it over after 1 hour, and again after 2 hours.
Turn the dough out onto a lightly greased or floured work surface. Divide it into 12 pieces, shape the pieces into balls, and firm them up by rolling them under your lightly cupped fingers on an unfloured work surface. Place the rolls on a parchment-lined baking sheet, cover them, and let them rise for 1 1/2 to 2 hours, until they've doubled in size. Refrigerate them for several hours, or overnight.
Remove the rolls from the refrigerator, and brush them with a wash made of 1/2 cup water mixed with 1 tablespoon egg white (you won't use up all the wash). Slash a 1/4-inch deep cut across the top of each roll, and bake them in a preheated 425°F (220°C) oven for 20 to 25 minutes, until they're a deep golden brown. Remove them from the oven, and cool on a wire rack. For an extra-crisp crust, allow them to cool in the turned-off, door-propped-open oven.