Heat the milk in the microwave for 30-40 seconds. Sprinkle the yeast over the milk and let it sit for a couple minutes. Add the milk and yeast to the bowl of a stand mixture. Add the sugar, eggs, butter, and mix until combined.
Add the flour and garlic salt. Turn the mixer to medium speed and let the dough mix for 5-7 minutes. If you don't have a stand mixer, you can hand knead the dough for 10 minutes instead.
Transfer the dough to a greased bowl and cover with plastic wrap. Set the bowl in a warm place until the dough has doubled, about 45 minutes.
Turn the dough onto a floured surface. The dough should be soft and easy to work with. Roll the dough out into a 12x20 inch rectangle. Add the pesto onto the dough and spread it out evenly with a 1/4 inch border on each side. Sprinkle the sun-dried tomatoes and cheese evenly over the dough. If your sun-dried tomatoes are large, chop them into small pieces before putting them on the dough.
Starting at one of the long ends, roll the dough up and seal it on the end by pinching it together. Cut the dough with a sharp knife every two inches. You should have about 12 rolls.
Add the rolls into a greased pan, cover, and let rise in a warm spot for 35 minutes. Heat the oven to 350. Before baking the rolls, brush them with melted butter. Bake the rolls for 20-25 minutes. When the rolls have about 5 minutes left, add a handful of mozzarella cheese on top and return them to the oven. Take them out when the cheese has melted and the dough is starting to brown.
Enjoy while the rolls are hot! Top with arugula (optional) and serve.
