Pound the lemongrass to a pulp using a pestle and mortar.
Toast coriander, cumin, turmeric, star anise, and cardamom in a dry pan and grind until smooth.
Melt coconut cream in a wide pan over low heat.
Sauté onions, garlic, chillies, ginger, and lemongrass until softened.
Fry ground spices and bay leaf for several minutes.
Brown the beef in the spice mixture over high heat.
Add coconut milk and hot stock, then bring to a boil.
Simmer for 1 to 1.5 hours until the sauce reduces to a thick paste.
Toast chutney spices until mustard seeds pop, then add mango slices and cook for 2 minutes.
Dissolve sugar into mango juices, add vinegar, and simmer covered for 25 minutes.
Rinse rice three times and drain.
Boil rice in water for 5 minutes, then turn off heat and steam for 20 minutes.
Serve beef rendang with rice and a spoonful of mango chutney.