Add salt and black pepper to the meat fillet all over. A large frying pan or flat plate should be heated at a high temperature. Cook the beef in 2 tablespoons of vegetable oil for 2-3 minutes on each side, or until well-browned (depending on how big your frying pan is, you may need to do this in batches). Reserve the meat for resting.

Coconut milk spontaneously separates into milk and cream layers when it is kept in a tin. Place a saucepan over medium heat and carefully pour the cream, which is the thicker layer, into the pan. Use the back of a spoon to combine the curry paste and the additional ingredient. Cook for 3–4 minutes, stirring often, or until a layer of crimson oil emerges; the sauce may appear to have split, which is accurate.

Then add the palm sugar and the remaining coconut milk to the pan. You want to reduce the sauce so that it is rather thick, so stir well and simmer for an additional 8 to 10 minutes over a fairly high heat.

Remove the stalks from the kaffir lime leaves and slice them into thin strips. Place another pot over medium heat with a tablespoon of vegetable oil when you are almost ready to serve. Cook for 20 seconds after adding the spinach, seasoning with salt and black pepper.

Remove the skillet from the heat as soon as the spinach begins to wilt.

The curry sauce in the pan will be heated through when you add the beef and fish sauce. Make sure the sauce is thoroughly incorporated into the beef.

Divide the spinach among the six dishes, then top each with a beef fillet, a dollop of coconut cream, and some shredded kaffir lime leaves.

Serving with steamed white rice is recommended.