Cheddar harissa garlic bread

Name: Cheddar & harissa garlic bread
Ingredients: 500g Morrisons Market Street round crusty loaf of white bread (a sourdough boule works well); 100g salted butter, softened; 2-3 tbsp harissa (depending on how spicy you like it); 3 large garlic cloves, grated; 75g mature cheddar, coarsely grated; 75g grated mozzarella