Silk Gourd with Green Soy Beans

Name: Silk Gourd with Green Soy Beans (Qing Dou Si Gua 青豆絲瓜)
Cuisine: Chinese
Ingredients: 1 tsp potato flour mixed with 1 tbsp cold water (optional); 150 ml stock; ½ tbsp Shaoxing wine; Salt; 45 g Chinese ham or Spanish ham, or 3 rashers of bacon; 2 tbsp cooking oil; 100 g shelled green soy beans; 1 silk gourd (about 500 g)