In a saucepan, add the milk and sugar. Heat over medium low heat until just warm, approximately 110℉ (you can check with the thermometer). Remove from the stove and pour the milk into the bowl of a stand mixer. Be careful - if the yeast isn't warm enough, it won't bubble. If it's too hot, the yeast will die.
1 cup milk, 1 tbsp granulated sugar
Add the packet of dry yeast to the milk and let sit for at least five minutes. The mixture should become bubbly and foamy. Then add the egg, flour, salt and room temperature butter. Add the hook attachment to the mixer and beat on medium speed for 4-5 minutes, scraping the sides down occasionally so everything gets mixed together.
1 packet active dry yeast, 3 cups all purpose flour, 1 egg, 1 tsp salt, 3 tbsp unsalted butter
Keep kneading the dough with the mixer for an additional 2-3 minutes. If the dough is super sticky (and would be hard to handle with your fingers), add flour one tablespoon at a time until it becomes pliable and soft (but still slightly sticky).
Grease a separate, large bowl with butter or olive oil and transfer the dough to this new bowl. Cover it with a towel and let it rise for 2 hours in a warm, dry area - like the kitchen counter.
After two hours, remove the towel. The dough should have doubled in size. Punch down the dough a few times to let out some air. Then divide the dough into 15 even pieces - a bench scraper will make this easier.
Grease your 9 x 13 dish with oil or butter. Roll each piece into a ball with a smooth top - use your fingers to stretch any imperfections so that the lumps are at the bottom of each roll, not the top. Space each roll out in the dish. Cover the dish and let rise for 1 more hour, until they appear puffy.
Preheat the oven to 400℉. Place the dish in the oven (uncovered) in the bottom rack of the oven. Bake for 20 minutes, rotating the dish halfway through. The tops should become golden brown but not burnt!
While the rolls are baking, prepare the topping. In a saucepan, melt the additional butter until bubbling. Turn off the heat and add in the rosemary and garlic. Stir well.
3 tbsp unsalted butter, 3 sprigs fresh rosemary, 3 cloves fresh garlic
While the rolls are still hot, brush the butter mixture onto the tops. sprinkle with sea salt Serve warm.
flaky sea salt