1. To make the spice paste,blend all ingredients to a thick paste in a blender or food processor. Alternatively,use a mortar and pestle to pound together.
2. Add the oil and spice paste to a large pot or Dutch oven over medium-high heat. Cook for 1 minute or until fragrant. Reduce to medium-low,add the spices and lemongrass and stir for 2-3 minutes until the paste starts to caramelise. Add the mushrooms and stir for 1-2 minutes to combine. Add the coconut cream,tamarind and 250ml water. Stir,cover and simmer on low heat for 10 minutes,allowing the mushrooms to cook down.
3. Meanwhile,toast the desiccated coconut in a small frypan on medium-low heat for 2-3 minutes until golden.
4. Add the toasted coconut,lime leaf,sugar and 2 big pinches of salt to the pot. Stir,cover and cook on low for 15-20 minutes until the mushrooms are tender and most of the liquid has evaporated. Season with more salt and sugar to taste;it should be spicy,sweet and rich. Serve with rice and coriander.
Tip: Classic rendang includeskerisik,a fried coconut paste. I cheated by using toasted desiccated coconut,but usekerisik if you have it.
*I used a combination of king oyster,oyster and shiitake mushrooms,but you could substitute with Swiss browns,shimeji,button,portobello or enoki varieties.