To make the spice blend: Mix together all of the ingredients; store in an airtight container., Bring the milk to a simmer and stir in the spice blend. Remove from the heat and let the mixture steep for at least 2 hours and preferably overnight (cover and refrigerate)., To make the dough: Heat the infused milk to lukewarm and place in a large mixing bowl. Add the sugar, butter, salt, yeast, and nigella seeds. Weigh your flour; or measure it by gently spooning it into a cup, then sweeping off any excess. Add the flour and mix and knead until a soft, smooth dough forms, about 6 to 7 minutes., Place in a greased bowl, cover, and let rise for 1 hour, until doubled., Grease a 13" by 4" Pullman loaf pan and the underside of its lid. Preheat the oven to 375°F., Deflate the dough and roll it into a 12" log. Place the log seam-side down in the prepared pan and cover. Set a timer for 30 minutes., After 30 minutes, push the lid back just enough to see how high the dough has risen. When it gets within 1/2" of the top, close the lid and put it in the oven to bake., Bake for 35 to 40 minutes, until the center reads 190°F when measured with a digital thermometer. Remove from the oven, slide off the lid, and turn the loaf out onto a rack to cool completely before slicing., Store bread, well wrapped, at room temperature for several days. Freeze for longer storage.