Heat the coconut oil in a heavy pan over medium heat. Add the curry leaves, green chillies, and 1 cup of water; bring to a gentle sizzle.
Sauté until the chillies soften and the water evaporates, then add the pre-boiled beef and toss to coat.
Meanwhile, grind the masala paste ingredients to a smooth paste, adding a splash of water if needed.
Stir the ground masala paste into the beef, followed by the garam masala powder. Mix thoroughly.
Add ½-1 cup water (depending on desired gravy thickness) and salt to taste. Bring to a boil, then reduce heat to low.
Simmer uncovered, stirring occasionally, until the gravy thickens and coats the beef, about 15-20 minutes.