Peel the garlic and onion, and cut the onion in chunks.
Add them to a blender together with 2 lemongrass stalks, 1 red chilli, deseeded, and the ginger puree.
Blitz to a paste.
Heat up the oil in a large pan, and add the beek chunks working in batches to avoid overcrowding.
Season the beef with salt and pepper, and brown on both sides.
Remove the beef from the pan and repeat with the second batch.
When all the beef is removed, add the onion paste to the pan, and quickly fry it for 2-3 minutes to deglaze the pan and caramelise the paste.
Add the browned beef, caramelised paste, coconut milk, bay leaves, tomato paste, cardamom pods, cloves, cinnamon stick, seeded chopped red chilli, star anise and the 3 lemongrass stalks left to the slow cooker.
Place the lid on the cook it on high for 4 hours or on low for 8 hours.
When it's ready, garnish it with chopped coriander.