Butter a 900g loaf tin and line with baking parchment that comes well above the longer sides. Make up the bread following the pack instructions. Leave the dough to rest under a cloth for 10 mins. Shape into a log on a lightly floured surface and divide it into six pieces. Mix the cheese, garlic, parsley and butter together.
Roll each piece of dough out into a rectangle, or as near to a rectangle as you can, the width should be just shorter than the width of the tin and the length about twice the depth of the tin, and lay the rectangles out side by side. Divide the cheese mixture between them (reserving 1 tbsp) and spread it out as much as possible. Fold each rectangle in half and then put them into the tin one after the other, starting at one end. You may need to squeeze them a bit to fit them all in. Don’t worry about the dough sticking out of the top of the tin. Cover the dough and leave to rise for about 30 mins or until risen. Crumble the remaining cheese mix over the top.
Heat oven to 180C/160C fan/gas 4. Bake for 40-45 mins or until golden and puffed (don’t under-cook it or it may be squidgy in the middle). Leave the loaf in the tin for 10 mins, then lift it out with the parchment. Serve it whole, ready to be pulled into pieces.