Hot'n Sour Soup

• 4 chinese mushrooms (dried)
• 2 squares
• 1 1/2 in dia
• 1 scallion
• 1 egg
• 1/2 bamboo shoots (canned)
• 950 ml chicken stock
• 65 gr pork (boneless)
• 45 ml water (cold)
• 30 ml vinegar (white)