Rotolo of wild mushrooms, fennel sausage and truffle

By Matt Tebbutt From Saturday Kitchen Ingredients 35g/1¼oz unsalted butter 15g/½oz plain flour 225ml/8fl oz full-fat milk 2½ tbsp olive oil 200g/7oz porcini mushrooms, thinly sliced 50ml/2fl oz double cream 2 slices Parma ham, roughly chopped 100g/3½oz mixed wild mushrooms, roughly chopped 1 garlic clove, finely …