Clean and wash the Brussels sprouts and cook in 1/8 litre salt water for about 20 minutes. Clean, wash and dice the potatoes and carrots. Cook in the broth for about 15 minutes. Rub chicken fillets with salt and pepper.
Heat the oil in a pan and fry the meat for about 10 minutes, turning occasionally. Remove some leaves from the Brussels sprouts, add milk and puree everything with the cutting stick of the hand mixer.
Season to taste with salt, pepper and nutmeg. Cut the chicken fillets open and arrange on plates with the sauce and bouillon vegetables. Serve garnished with the Brussels sprouts.