Potatoes Stuffed with Stilton, Leek and Mushrooms

Name: Potatoes Stuffed with Stilton, Leek and Mushrooms
Yield: Serves Four
Cuisine: United Kingdom
Ingredients: 100-175 g (4-6 oz) Stilton cheese; coarse sea salt and pepper; 100 g (4 oz) cream cheese, at room temperature; 1 large leek, sliced; 100 g (4 oz) button mushrooms, quartered; 50 g (2 oz) butter, plus an extra knob; 4 large baking potatoes