Combine the milk with yeast and 1 teaspoon sugar and let sit for 5 minutes or until the yeast is activated and the mixture is foamy.

In the bowl of a stand mixer, add the flour, 2 tablespoon sugar, 1 ½ teaspoon salt, beaten egg, and ½ cup melted butter. Add the yeast mixture and knead the dough until smooth, about 5-7 minutes. Add 1 tablespoon chopped rosemary and the grated gruyere and knead for another minute or until well combined. Transfer the dough to a clean bowl, cover, and let rise for 1 hour in a warm area or until doubled in size.

Grease a 9x13 baking pan.

Punch down the dough and divide it into 18 equal portions. Roll each portion into a ball and arrange them in the prepared pan with 3 rows of 6 rolls. Cover the pan and proof for 30 minutes.

Preheat oven to 350 degrees F.

Brush 2 tablespoon melted butter on the tops of the rolls and sprinkle 1 teaspoon chopped rosemary and ½ teaspoon sea salt. Bake the rolls for 30-35 minutes or until the tops are browned. Remove from heat and let cool slightly. Serve warm.