1) In a small mixing bowl, pour the boiling water over the 1 cup of cereal. Allow the mixture to cool to lukewarm, about 45 minutes.
2) While the water/cereal mixture cools, blend together the flour, soda, and salt in a large mixing bowl. Stir in the raisins or currants. Set it aside.
3) Stir the vegetable oil into the cooled water/cereal mixture. Set it aside.
4) Whisk together the eggs, buttermilk, and sugar. Combine this with the flour/raisin mixture.
5) Stir in the dry cereal.
6) Finally, add the water/bran/oil mixture, stirring till thoroughly combined. Cover the bowl and refrigerate overnight.
7) Preheat your oven to 375°F. Lightly grease a standard muffin pan, or line with paper cups, and grease the cups. Use as many wells as you like; since this recipe can live in the fridge for a couple of weeks, there's no need to bake 12 muffins all at once.
8) Heap the thick batter in the muffin cups; a generous 1/4 cup batter (about 3 1/2 ounces, or 100g) is a good amount to use.
9) Bake the muffins for 20 to 25 minutes, till a cake tester inserted into the center of a muffin comes out clean.
10) Remove from the oven, and tip the muffins in the pan to prevent their bottoms steaming and becoming soggy. Serve warm; or transfer to a rack to cool completely.
11) To bake mini muffins, heap the batter in the muffin cups, and bake for about 15 minutes, till the muffins test done.
Yield: 18 standard muffins, or 45 mini muffins.