Preheat the oven to 165 degrees Celsius.
Prepare the pork fillet by seasoning it with salt and pepper. Heat a griddle pan until very hot, sear the pork on all sides to seal in the juices, and add colour for about 2 minutes per side.
While the pork is searing, prepare the garlic confit. Separate the garlic bulbs into cloves (no need to peel) and place in a small saucepan with the oil. Simmer gently over low heat for 10-15 minutes until the garlic becomes soft and jammy.
Cut the baguette in half lengthwise and hollow out the centre to create a channel for the pork. Brush the inside with some garlic oil and spread the softened garlic cloves along the base.
Once the pork is seared, remove from the heat and coat evenly with Dijon mustard. Roll the mustard-coated pork in the chopped herbs, pressing gently to adhere.
Place the herb-crusted pork inside the hollowed baguette and close the top half. Secure with kitchen twine at 2-inch intervals along the length of the baguette.
Transfer to a baking sheet and bake for 25 minutes. For larger fillets, you may need to increase the cooking time to ensure the pork reaches an internal temperature of 63 degrees Celsius.
Five minutes before the end of cooking time, sprinkle the top of the baguette with grated Parmesan cheese and return to the oven to melt.
Allow to rest for 5 minutes before removing the string and slicing it into thick portions.
