Peel, wash and slice the carrots. Clean and wash mushrooms and Pak Soi. Cut the Pak Soi into small pieces. Cut lemongrass lengthwise, remove outer leaves and chop the inside finely. Clean the chilli, cut lengthwise, remove seeds, wash and chop finely. Rinse meat, dab dry and cut into small pieces.
Bring 600 ml water, soy sauce, coconut milk and broth to the boil in a large ovenproof pot. Add prepared ingredients and rice and mix everything. Cover and cook in the preheated oven (electric cooker: 200 °C/circulating air: 180 °C/gas: see manufacturer) for about 40 minutes.
Season soup with salt and pepper. Krupuk (Asian crab chips) go well with it.