Smoked Haddock Mousse from Marvellous Meals with Mince by Josceline Dimbleby

Ingredients

• 100 g butter, plus extra for greasing
• 125 g peeled prawns
• 500 g smoked haddock fillets, skinned
• 3 large eggs, separated
• 300 ml double cream
• 3–4 pinches of mild chilli powder
• sea salt
• 300 ml whole milk
• 8–12 strands of saffron
• 1 level tbsp plain flour
• 1 tsp tomato purée
• 2 sprigs of dill, finely chopped, plus extra for serving
• 2–3 tsp white wine vinegar