Sweet and Sour Courgettes

Name: Sweet and Sour Courgettes (Tang Cu Yi Da Li Gua 糖醋義大利瓜)
Cuisine: Chinese
Ingredients: 1 tsp Chinkiang vinegar; ½ tsp caster sugar; 2 tbsp cooking oil; 2 garlic cloves, finely sliced; 2 courgettes (300 g); Salt