How to cook venison

INGREDIENTS

• 500g/1lb 2oz venison
• 3 tbsp vegetable oil
• salt and freshly ground black pepper
• 300g/10½oz fine green beans
• 100g/3½oz bag watercress
• ½ shallot
• handful of walnuts
• 1 tbsp walnut oil
• 1 tsp English mustard
• 1 pickled walnut, thinly sliced, plus 2 tsp juice from the jar
• 1 gherkin
• ¼ tsp freshly ground black pepper
• 1 tsp Worcestershire sauce
• 1 sprig tarragon
• ½ tsp red wine vinegar