1. Preheat the oven to 275°F (140°C). Place the saffron in a small baking dish. Bake for 10–15 minutes to toast the saffron. Let cool, then crumble to a fine powder. Stir into the boiling water and let stand about 1 hour, or overnight.

2. Sift the flour and salt into a large bowl. Add the butter and rub it in with your fingertips until the mixture resembles coarse bread crumbs. Stir in the sugar and yeast. Beat together the milk, ½ cup water, egg, and dissolved saffron. Add to the flour mixture and stir to make a soft dough.

3. Turn the dough out onto a lightly floured surface and knead for 8–10 minutes, or until smooth and elastic. Knead in the currants.

4. Divide the dough into 12 pieces. Shape each piece into a ball and flatten slightly. Place the balls on an oiled baking sheet. Cover loosely with lightly oiled plastic wrap. Let stand in a warm place for 30–40 minutes, or until they have doubled in size.

5. Preheat the oven to 425°F (220°C). Bake in the upper third of the oven for 15–20 minutes, or until the buns are light gold and sound hollow when tapped on the bottom. Transfer to a wire rack and let cool. Serve warm or cold.