Use a food processor to mince the chilies, garlic, ginger, chili powder, and lime juice, or mince everything finely by hand and combine.
Heat the oil over medium-high heat in a large skillet with a lid. Add the minced spice mixture to the hot oil and cook, stirring occasionally, until fragrant, about 2 minutes. Add the beef and cook, stirring occasionally, until browned and covered with sauce. Pour in the coconut milk, scrape up any browned bits on the bottom of the pan, and bring to a boil. Lower the heat and cook at a very low simmer, stirring occasionally, until the meat is very tender. Cook for at least one hour, probably closer to two.
Uncover the skillet and continue to cook until the sauce is caramel-colored and very thick. Stir frequently so that it doesn't brown. Taste and adjust the seasoning if needed. Serve hot, and enjoy!