Black sesame seeds may be available at health food stores or Japanese markets. In a bowl, dissolve the yeast in the water. Allow to proof for three minutes. Stir the sponge into the water, breaking the sponge up using your hands or a spoon. Add 3 1/2 cups of the durum flour, cornmeal, 2 tablespoons of sesame seeds, and the salt and mix, scraping and folding until the dough gathers into a single mass. Turn the dough out onto a lightly floured surface, and knead the dough until smooth and elastic, gradually adding as much of the 1/3 cup of durum aas needed (but as little as you can get away with). Shape into a ball and place the dough in a lightly oiled bowl, cover with plastic wrap and refrigerate overnight. After removing the dough from the refrigerator, allow to sit for two hours in a draft-free location. Sprinkle a baking sheet, without sides, generously with cornmeal. Flour a worksurface. Halve the dough and flatten each half gently into a 10x12 inch rectangle. Roll each rectangle tightly along a 10 inch side, making two 12 inch cylinders. Roll from the center towards the edge to make 20 inch ropes. Coil the rope from one end, pulling up the center knot. Place the coils on the baking sheet. Mist the loaves lightly using a plant sprayer. Spoon a tablespoon of the seeds along each of the coils. Cover with plastic wrap and allow to double in a draft-free location. This should take 1 to 2 hours. Preheat the oven for at least thirty minutes along with a baking stone or tiles on the middle rack to 425. Place a baking pan with decent sides on the bottom shelf. Boil two cups of water. Pour the boiling water into the baking pan. With a quick jerk, slide the loaves off the sheet and onto the stone. Bake for 25 minutes until the loaves are hollow sounding when tapped on the bottom. When done, cool on a rack. Note: Durum wheat is the hardest variety of wheat and makes a very high-gluten flour. Durum is made from the same wheat as semolina, but is finely ground and is superior for making bread. It can be found in health food stores, specialty food markets, and some Italian markets. From: Bread-Bakers Archives: ftp.best.com/pub/reggie/archives/bread/recipe Recipe By : Amy Scherber, Food&Wine 2/93