Method:

1. Gently warm the milk in a pan until lukewarm or body temperature, 37ºC. Add the yeast and sugar and stir until the sugar is dissolved. Set aside for a few minutes until the mixture is creamy and starting to froth.
2. Melt the shortening or lard. In a large bowl, mix the yeast mixture, flour, shortening or lard and a pinch of sea salt into a soft dough. Add a little extra milk or flour, if needed.
3. Knead until smooth and elastic. Transfer to a greased bowl, cover with cling film and set aside in a warm place to rise for 1 hour, or until doubled in size.
4. Knock back the dough and roll out on a lightly floured surface to about 2cm thick. Using a round cutter or thin drinking glass, cut out circles of 5 to 8cm.
5. Lightly sprinkle a piece of baking parchment with extra flour, or polenta (if using). Transfer the muffins to the paper and sprinkle over a little more flour or polenta. Cover with a tea towel and leave in a warm place for 45 minutes to 1 hour to rise.
6. When ready to cook, preheat the oven to 170ºC and heat a heavy non-stick pan over a medium heat.
7. Brown the muffins in the pan, in batches, for a few minutes each side, then turn the heat to low and cook for 10 minutes. Transfer to a baking tray and finish with 5 minutes in the oven, or until cooked through.
8. Cool slightly on a wire rack then split open and spread with melted butter, or keep in an airtight tin, to split and toast as needed.