1. In a large glass bowl, combine the water, yeast, agave nectar, and cornmeal. Let sit in a warm place for 10 to 15 minutes, until foamy. Stir in 4 cups of the flour, the sea salt, and the oil. Turn the dough out onto a lightly floured board and knead just until all ingredients are well incorporated and dough is smooth. (Add more flour as needed if sticky). Lightly oil a large glass bowl and place the dough ball into it. Cover the bowl and set aside in a warm place to rise for 1 hour.
2. In a medium skillet over medium- high heat, cook the bacon until just crisp. With a slotted spoon, transfer the bacon to a paper-towel- lined plate. Add the onion to the rendered fat and cook for 15 to 20 minutes, until soft and deep brown.
3. In a small bowl, combine the mayonnaise, chili sauce, chipotle, and 1/4 cup cilantro and blend well. Refrigerate until needed.
4. Preheat the oven to 375 degrees F. Lightly grease and flour a 9-by-5- inch loaf pan.
5. Turn the dough onto a floured surface, sprinkle it with flour, and knead gently until smooth, folding over several times. Flour a rolling pin and roll the dough into a rectangle about 12 by 9 inches.
6. Spread the dough generously with the chipotle mayonnaise. Cover with the brisket, then the onion, roasted pepper, and bacon. Sprinkle evenly with the Havarti, the remaining cilantro, and cracked pepper.
7. From the short side, gently roll up the dough "jelly roll" style, tucking in the ends as you go. Place the dough roll in the prepared loaf pan, brush with the melted butter, and sprinkle the top with the dry Jack. Bake for 1 hour 25 minutes, until dark golden brown. You should hear a slightly hollow sound when you tap the bread.
8. Cool for a full 30 minutes in the pan on a wire rack. Then remove from the loaf pan and slice into 1- inch thick slices. Enjoy immediately.