In the bowl of a stand mixer add the milk and yeast. (See notes if using active, not instant, yeast). Add the flour, sugar, butter, and salt. Mix on low and add the poolish. Mix with the dough hook for 8-10 minutes at medium speed (3 or 4 on a Kitchen Aid). Should be a fairly smooth dough, so depending on humidity you may need to add more flour a teaspoon at at a time. (If your stand mixer is like mine, may need to stop and scrape the sides down a few times.)
Add the dough to a lightly oiled bowl, cover with plastic wrap (or a shower cap) and let rise in a warmish place for 1-2 hours until doubled.
Divide into 12 pieces -- should be 72-75 grams each, but if you're nuts like me measure and divide to make sure. On a floured surface, form into balls. Cover with plastic wrap or a clean, dampish towel and let rest for 15 minutes.
Line a baking sheet with parchment and liberally dust with semolina or corn meal. Liberally. Really. (See Notes.)
Dust the tops of the balls with semolina or corn meal. Taking a plate or a spatula, press the balls down flatter and transfer to the liberally-dusted parchment. Sprinkle the top with more corn meal or semolina, cover with a sheet of parchment, and put an upside down sheet pan on top to keep them in their flattened shape.
Let rise for 30-45 minutes. They won't double, but they should be really puffy.
Heat a cast-iron griddle, a large frying pan, or an electric frying pan on low. Let heat for 5 minutes to get an even heat across the entire surface.
Heat oven to 350℉ (175℃).
Remove the inverted sheet pan and parchment paper you had on the top and set aside.
Liberally dust your frying surface with semolina or corn meal.
Using a spatula carefully transfer 4-6 muffins from the sheet pan to the frying surface -- depending on how many will fit easily -- being careful to not knock the air out of them. Fry on each side for 5-7 minutes until golden brown and firm.
When done browning, transfer to the formerly inverted sheet pan and put in the oven. Heat for 10-12 minutes until an instant-read thermometer put through the side into the middle registers 200℉ (94℃). Transfer to a cooling rack and let cool for at least 45 minutes.
Repeat with the rest of the muffins. (If you time it right, while the first batch is in the oven you can be browning the second batch, and about the time the first batch is done baking through, the second batch will be ready to go in to the oven. And so on.)