To make the starter: Stir all of the starter ingredients together to make a thick, pudding-like mixture. Cover with plastic wrap and let it rest for at least 2 hours. For best flavor, let the starter rest longer; overnight (up to 16 hours) is best.
Place all ingredients for starter on the bowl of your mixer, with the bread hook on, mix the ingredients together. Turn the machine off, cover the bowl with a light kitchen towel and let the starter rest as directed above.
To make the dough: Stir down the starter with a spoon and add the water, yeast, sugar, 3 1/4 cups of the flour, and the salt. The dough will be a loose, messy mass. Let it rest for 12 to 15 minutes, then stir it again. It should become more cohesive and a bit smoother.
Transfer dough to a flat surface, knead the dough, adding more flour as necessary, 10 to 12 minutes.
Place the dough in a lightly greased bowl or plastic container, cover with lightly greased plastic wrap, and let it rise until almost doubled (about 1 to 2 hours).
Deflate the dough gently, but don't knock out all the air. For one large loaf, form the dough into a round ball. For two loaves, divide the dough in half and shape into two balls. Place a cornmeal-dusted piece of parchment paper onto a baking sheet.
Gently place the ball(s) of dough on the baking sheet, seam-side down. Cover the bread gently with lightly greased plastic wrap, and let rise until it's puffy and about 40% to 50% larger, anywhere from 45 to 90 minutes.
Start Traeger grill on smoke with the lid open until fire is established (4 to 5 minutes). Set temperature to High and pre-heat, lid closed, for 10 to 15 minutes.
Slash or cross-hatch the bread with a sharp knife. Dust it with a little flour.
Reduce the heat to 425 degrees F and spritz with water every few minutes for the first 15 minutes of baking. Bake the bread for about 25 to 30 minutes, or until it's a rich golden brown, and its interior temperature registers at least 190 degrees F on a digital thermometer. Smaller loaves will bake more quickly, so keep your eye on them.
Remove bread from Traeger grill, and let it cool on a rack. Slice and serve. Enjoy!