1.Heat oil in a large frying pan over moderately low heat. Add onion; cook and stir for 8 minutes or until soft. Add vinegar; cook and stir for 1 minute or until combined. Stir in gravy powder; cook and stir for 1 minute or until combined. Remove from heat. Gradually whisk in 2 1/4 cups water until well combined. Place over moderate heat. Bring to the boil, stirring. Reduce heat; simmer for 2 minutes or until mixture thickens.
2.Heat a large frying pan over moderately high heat. Add sausages; cook and turn for 8 minutes or until cooked.
3.Place potato in a large saucepan; cover with cold water. Bring to the boil. Boil for 8 minutes or until tender, adding broad beans in last 2 minutes of cooking. Drain; return to pan. Add garlic and milk; mash until almost smooth. Season. Divide mash onto serving plates. Top with sausages and gravy. Serve.
Omit balsamic vinegar. Use brown or apple cider vinegar instead. Use floury potatoes.Note