Make the dough: Add warm milk, yeast, and sugar to a large bowl. Add flour, salt, and melted butter. Mix until a soft, slightly tacky dough forms.
Knead: Transfer the dough to a lightly floured surface and knead for about 6–8 minutes, until smoother and elastic.
Add blueberries: Gently flatten the dough and scatter the blueberries over it. Fold the dough over the berries and knead very lightly to distribute them without crushing the fruit.
First rise: Place the dough in a lightly greased bowl. Cover and let it rise in a warm place until noticeably puffy, about 1–1½ hours.
Shape: Divide the dough into 8 equal pieces. Shape each piece into a thick round without pressing it too flat.
Dust: Sprinkle cornmeal or semolina over a baking sheet. Place the muffins on it and lightly dust their tops.
Rest again: Cover the shaped muffins and let them rest for 20–30 minutes.
Cook: Heat a dry skillet or griddle over low to medium-low heat. Cook the muffins for about 6–8 minutes per side, turning carefully when the bottoms are golden brown.
Check the center: If the outside is browning too quickly, lower the heat and continue cooking until the centers are fully cooked.
Cool and serve: Transfer to a wire rack and let them cool for several minutes. Split with a fork, toast if desired, and serve warm.