1. Scald the milk in a small saucepan while constantly stirring. Remove from the heat, add the sugar, 1 teaspoon salt, and the butter and mix well until the sugar and salt have dissolved and the butter has melted. Transfer to a bowl.
2. Add the 1/2 cup of lukewarm water to a separate bowl, then add the yeast and mix well. Leave for a few minutes until the liquid begins to froth. Add the onion and cilantro and mix well.
3. Combine the flour and both liquids until you have a very sticky dough. Cover the bowl with plastic wrap, and let rise in a warm place for about 45 minutes or until doubled in size.
4. Meanwhile, preheat the oven to 350°F, and grease a 9 x 4 3/4-inch loaf pan.
5. Knead the dough well, then transfer to the greased loaf pan. Sprinkle with sugar, salt, and cracked black pepper, and bake in the oven for 1 hour.
6. Turn out bread onto a wire rack and garnish with extra cilantro, then let cool.