Cut the beef into strips about a quarter of an inch thick and three inches long.
Pound the garlic, shallots, ginger and chilis to a paste. Use a mortar and pestle, a blender or a food processor.
Heat the cooking oil in a wok or frying pan. Add the paste and cook until fragrant, about a minute.
Add the beef to the pan. Stir to coat each piece with the spice paste.
Add the kaffir lime leaf, tamarind juice, palm sugar, soy sauce and shrimp paste. Pour in the liquid in which the beef was pressure-cooked.
Bring to the boil, lower the heat, cover and simmer for 20 to 30 minutes or until the beef is tender and the sauce has thickened and reduced. Taste the sauce, adjust the seasonings if needed.
Sprinkle with finely sliced chili and scallions, and serve hot.