Melt butter on a slow fire in a deep pan. Add onions and sugar. Cook on a low fire for 15 minutes until onions are a pace golden colour and soft. Add cabbage, stir fry till tender. Add flour and cook for few minutes. Add stock, Melam pepper powder, salt and vinegar and bring to boil. Cover and simmer for 20 minutes. Add chicken shreds, boil. Spread butter on the smooth sides of bread slices. Spread cheese spread. Bake in an oven till bread slices are crisp and cheese melts. Place bread slices in each serving bowl and pour the soup over. Serve hot.