Heat coconut oil in a pan over medium heat and add mustard seeds. Once seeds start to pop, add onions, serrano pepper and curry leaves.
Once onions begin to brown, add garlic and ginger.
Add the spices and let them bloom - then add ground beef.
Cook the beef until it's mostly browned, then add the carrots, potato and ¼ cup of water.
Cover the pan and cook for 5 minutes.
Add coconut milk and simmer until the potatoes are tender (approx. 15 minutes).
Adjust salt and pepper and add water if you prefer a thinner curry.