Preheat oven to 350 degrees F. Lightly grease a cast iron pan or baking dish.
Place flour in a large bowl. Add the yeast and mix to combine. Set aside.
Heat milk in a small saucepan until hot to touch (do not boil). Take off heat and add shortening, sugar, and salt. Stir until shortening melts into the milk mixture (a few lumps are okay). Stir in hot water to combine.
Make a well in the flour mixture and pour in milk; mix to combine with a spatula. Turn dough out onto a floured surface. Knead for 6 minutes, gradually adding flour until the dough is no longer sticky.
Place dough in a large, greased bowl, turning once to grease both sides. Place bowl in a warm place and cover with a clean dish towel. Let rise for 90 minutes.
Turn dough out onto a lightly floured surface. Pull off 3-inch sized pieces of dough and place in a greased cast iron pan about a ½-inch apart. Place pan in a warm spot and cover with a clean dish towel. Let rise for 1 hour before baking.
Herb Butter: While the dough is rising for the second time, melt butter in a small sauce pan over medium-low heat. Add crushed garlic and chopped rosemary. Simmer for 2 minutes to let the flavors marry.
Using a pastry brush, brush dough with the herb butter. Sprinkle with sea salt.
Bake for 25-30 minutes, or until the tops are golden brown. Serve warm with a generous helping of butter.
Recipe by The Messy Baker Blog at http://themessybakerblog.com/2013/01/01/grandmoms-rolls/