Marmite consommé

Ingredients

• 750g brown butter, strained (see tip, p.204)
• 1kg peeled and finely sliced onion (approx. 5 large onions)
• 1kg cleaned and finely sliced leek, white part only (approx. 20 leeks)
• 500g peeled and finely sliced carrot (approx. 6–7 large carrots)
• 750g red wine
• 3 large egg whites
• To finish and serve
• 10g sherry vinegar (or to taste)
• ½ tsp marmite (or to taste)
• Salt and black pepper