Heat the oven to 190C/170C fan/gas 5. Cut into the bread loaf at 2cm diagonal intervals using a serrated knife, going almost all the way though, then repeat in the opposite direction so you create a diamond pattern. Put the loaf on a baking tray lined with baking parchment.

Put the butter, harissa and garlic in a small bowl and beat together using a spatula or wooden spoon. Season with a little salt and pepper.

Spread the butter into the cuts of the bread loaf, then sprinkle both of the cheeses into the cuts and over the top of the loaf, making sure every gap is filled with butter and cheese. Wrap well in foil.

Bake for 20 mins, then remove the foil from the top and return to the oven for 10 mins more until melted, golden and gooey. Serve whole so everyone can tear and share.