Roasted partridge with moutabal, watercress and cabbage salad

Ingredients

• 2 aubergines
• juice of half a lemon
• 2 tbsp thick Greek-style full fat yoghurt
• 1 heaped dsp of tahini (sesame) paste
• 2 tbsp finely chopped watercress leaves
• 4 partridges
• 100g watercress leaves – no tough stalks
• 1 tbsp tarragon leaves
• ½ a white cabbage, finely grated on a medium grater
• 2 tsp Dijon mustard
• 1 tsp sugar
• 1 tbsp cider or white wine vinegar
• 4 tbsp cold-pressed rapeseed oil
• 30g butter