Start with the tangzhong by placing bread flour and milk in a saucepan. Heat over medium-high heat and whisk until it comes together, about 1 minute. Set aside and allow to cool down.

Combine the yeast and milk and let it rest for 5 minutes, allowing the yeast to become active. Combine the bread flour, salt, cardamom, and sugar in a large bowl of a stand mixer. Add the tangzhong, milk, and egg to the bowl and mix until it just comes together.

While the dough begins to knead, add the butter one tablespoon at a time. Knead the dough for 5 minutes. If the dough is too sticky, add 1 tablespoon of flour at a time. If it is too dry, add one tablespoon of milk at a time.

Transfer to an oiled bowl, cover, and let rest for 1 hour or until it has doubled in size. Once doubled, punch down and knead. Split the dough into three equal portions.

Grease a deep bread baking pan. Take one of the portions and roll the dough out into a long rectangle. Make sure the width of the rolled out portion is not wider than the baking dish you are using. Carefully roll up the dough. Place in the prepared baking pan. Repeat with the other portions.

Cover and allow to rise again for 30 minutes, or until it double in size. Preheat oven to 350°F. In a bowl, combine the egg and milk for the egg wash. Brush the top of the bread with the egg wash. Place in the oven and bake for 30 minutes, or until golden brown and cooked through.

To prepare a portion of curry, cut a 1-inch slice of toast. Brush with butter and place under the broiler. Cook until the edges just begin to brown. Prepare a portion of curry on a plate. Cut the piece of toast in half and place on top of the curry.