Preheat oven to 425°F (218°C).
If mixing this by hand, simply place the warm milk, yeast, and sugar in a bowl and stir. Allow the yeast a few moments to "bloom" and become frothy.
To the bowl, add 1/2 tsp. of salt, 4 tbsp. butter, and 4 cups of flour, starting with one half cup flour at a time. Mix well in between each addition of flour.
Mix with a wooden spoon, a Danish dough whisk, or clean hands until the dough comes together in a smooth ball and is no longer sticky. This may take 10 minutes of kneading. You may need an additional one half cup flour for a total of 4 1/2 cups flour.
Take a clean, large bowl and pour in the olive oil. Drop the dough into the bowl and turn it around until the dough is completely greased.
Cover the bowl with plastic wrap, place it in a warm area, and allow the dough to double in bulk. This will take about 1 1/2 hours.
After the dough has doubled in bulk, divide the dough into 12 even pieces and roll into 12 balls. (See video.)
Place each ball into a greased cast-iron skillet or onto a greased baking sheet.
Brush the dough balls with a 1/4 cup of water using a pastry brush. Make sure the dough balls are each well saturated.
Cover dough balls with plastic wrap and allow them to rise in a warm area for 30 minutes until doubled in size.
After 30 minutes, uncover the dough balls. Using a sharp knife, make a cross incision on the top of each dough ball.
Place the cast iron skillet onto the middle rack of the oven and bake for 20 minutes.
After 20 minutes or once the rolls are golden brown, remove the skillet or baking sheet from the oven and place it on a heatproof surface.
Melt the remaining 4 tablespoons of butter, brush the butter on top of the rolls, and sprinkle the rolls with the remaining 1/2 teaspoon of salt. Serve immediately.