Christmas Turkey, Gammon & Walnut Pot Pie - California Walnuts

Ingredients

• 150 g butter
• 200 g plain flour
• 1 large carrot (finely diced)
• 100 g frozen peas
• 25 g butter
• 25 g plain flour
• 400 ml milk
• 2 tsp wholegrain mustard
• 250 g cooked turkey meat (shredded)
• 250 g cooked gammon (shredded)
• 75 g California Walnuts (roughly chopped, plus 25g chopped)
• 1 medium egg (beaten)