Add the oil, garlic, optional red pepper flakes and tomato paste to a deep skillet and cook on low heat until the tomato paste is caramelized and brick red in color.
Add the tubetti pasta and broth, cook for about 10-12 minutes until about 80% of the liquid is absorbed.
Mix in the cold butter and stir until melted. Mix in the cheese and stir until melted.
Serve in bowls and top with more cheese.
