Preheat the oven to 180C / 350F. Line a small shallow dish with baking paper (the dish I use measures approx 11cm x 3cm).
Add all the ingredients (except the rosemary and pepper) to a blender and whizz on high speed until smooth.
Transfer to a saucepan and cook on medium heat, stirring continuously until it is smooth and has started to thicken (about 2 minutes). Initially, as it warms up, it will go lumpy but don’t worry this is normal. Keep stirring and it will soon smoothen out. Taste test and add a touch more salt, if needed.
Pour into the prepared dish and smooth the top. Garnish with rosemary needles (I push some of the needles in whole and finely chop a few to sprinkle). Add some freshly ground black pepper, if desired.
Bake for 20 minutes, or until the cheese has formed a skin and is lightly browned round the edges. (You can also warm some bread in the oven at the same time, if you wish).
Serve immediately or leave to cool before transferring to an airtight container. It will keep for up to five days in the fridge. Bring to room temperature or re-heat in the oven for a few minutes before serving.