Slice the tempeh into bite-sized pieces. Slice the green chillies diagonally, halve the red chillies, peel the garlic and shallots, bruise the lemongrass, and peel and halve the galangal.
Crush the garlic and shallots using a mortar and pestle or food processor until a rough paste forms.
Heat the coconut oil in a large pot over medium heat. Sauté the garlic and shallot paste until fragrant.
Add the green chillies, red chillies, galangal, lemongrass, kaffir lime leaves, and bay leaves. Cook for 1 minute until fragrant.
Stir in the tempeh and cook for another 2–3 minutes, stirring frequently.
Pour in the water and bring to a boil.
Reduce the heat to a gentle simmer, stir in the coconut milk, and continue cooking for 5–10 minutes, or until the broth turns a light green colour.
Remove from the heat and stir in the salt, palm sugar, and seasoning.
Remove and discard the lemongrass stalk, galangal, bay leaves, and kaffir lime leaves. You can also remove the green and red chillies before serving if you prefer not to eat them. Serve warm on its own as a comforting soup or with steamed rice.