Add carrots, butter, salt, and pepper to a 2-quart or larger pot. Add 1 cup water and bring to a boil over high heat. Stir, cover pot, and reduce heat to low and cook for 20 minutes. Remove lid, stir again, and if a lot of water remains, increase heat to medium-high and continue to cook until most of the liquid has evaporated and carrots are tender and sweet, 8 to 10 minutes longer. Add te parsley and mint, and gently stir to combine.