Chicken, leek and cider gratin
This is made possible by BBC Foods! Ingredients 50g/1¾oz butter 500g/1lb 2oz boneless, skinless chicken thighs, cut in 4cm/1½in cubes 2 large leeks, trimmed and sliced 150ml/¼ pint cider 1 heaped tsp Dijon mustard 1 tsp soy sauce ¼ tsp smoked paprika, sweet or hot, plus a little extra for sprinkling 300ml/10fl oz double cream 350g/12oz potatoes, such as Maris Piper, scrubbed and very…