Corned beef with cauliflower mash

Ingredients

• 1 1/2 kilograms piece corned silve side
• 2 small brown onions, thinly sliced
• 1 medium carrot, chopped
• 1/4 cup balsamic vinegar
• 8 whole cloves
• 2 tablespoons brown sugar
• 500 grams potatoes, cut into 2cm pieces
• 400 grams cauliflower, cut into florets
• 25 grams butter
• 1/3 cup cream
• 2 tablespoons cornflour
• 1 1/2 cup milk
• 1 1/2 tablespoon wholegrain mustard
• 1/4 cup finely chopped flatleaf parsley
• steamed green beans, to serve