Tip the flour into a large mixing bowl or stand mixer (if using). Sprinkle the yeast on one side of the flour and the salt into the other side of the flour. Add the sugar, butter, egg and milk, then mix all the ingredients together to form a soft dough. Knead for 3 minutes, in stand mixer.
If kneading by hand, turn the mixture out of the bowl onto a lightly floured surface and knead for 10 minutes, or until soft, smooth and stretchy.
Lightly grease a large bowl with oil. Place the dough in the oiled bowl, cover with lightly greased cling film, and leave to prove for about one hour, or until doubled in size.
Dust the work surface with a mixture of the semolina/polenta and flour. Tip the dough out onto the work surface and roll it out to about 2.5cm thick.
Lightly dust two baking trays with half of the semolina or polenta.
Using a 9cm straight-sided cutter, cut out eight muffins. Place four muffins, evenly spaced apart on each of the dusted baking trays. Dust the remaining semolina or polenta over the top of the muffins.
Leave to prove for another 30 minutes.
Preheat a griddle pan or heavy-based frying pan on the hob to a very low heat. Griddle the muffins for approximately 5 to 6 minutes, then flip over and griddle for another 5 to 6 minutes on the other side. Eat them warm with lashings of butter, or save for later on or another day when they can be sliced in half and toasted - yum!