Preheat the oven to 180°C/350°F.
In a heatproof bowl, combine the butter, garlic, and salt, then melt in the microwave. Stir in the chopped parsley.
Cut the bread diagonally into 2cm/1-inch diamond shapes, making sure not to cut all the way through the loaf.
Using your fingers or a knife, gently open each crack and drizzle a teaspoon of the garlic butter into each section, then stuff a pinch of cheese into each. It may feel a bit tedious, but trust me, it's totally worth it! Don’t worry about being too neat; some of the butter will naturally drip onto the crust, and that’s part of the charm.
Brush any remaining butter over the surface of the bread.
Wrap the loaf in foil and bake for 20 minutes until the cheese is mostly melted. Then, uncover and bake for an additional 5-10 minutes to crisp up the crust.
Serve immediately. (See Note 1 for the best make-ahead methods.)