Mix 3 cups flour, 1 tsp. sea salt, and 2 Tbsp. chai mix together in a bowl.
Combine 1 1/2 cups warm water and 1/2 cup sourdough starter in a liquid measurer.
Add the water mixture to the flour mixture and add the 2 Tbsp. of softened fat. Mix by hand or with a stand mixture with the bread hook attached until the dough clears the sides of the bowl.
Form into a ball and cover the bowl. Allow to rest covered for 30 minutes.
Peform a stretch and fold every 30 minutes, 3 times.*
Cover and set aside in a warm place to ferment for at least 6 hours.
After 6 hours, remove the dough from the bowl and perform one last stretch and fold. Shape and place into your bread pan. Cover with enough room to rise and set aside until the dough has doubled in size. Depending on ambient temperature, this could take 1-3 hours, or more.
Remove the cover, slash the dough several times, replace with a baking safe cover (like a metal lid or an inverted bread pan) and bake at 400F/204C for 45 minutes.
Remove the cover for the last 10 minutes of bake time to brown the top. The finished loaf should register between 200F - 205F (93C - 96C).
Remove from the oven and place the loaf on a baker's rack to cool completely. It takes a bread loaf 12 hours or longer to completely cool. If you choose to cut into this loaf while it's hot, be gentle and don't crush the crust. The crumb may be a little gummy after cutting hot. I don't judge, though; this bread is best when served hot with melted butter.