Parmentier Potatoes with Herb Salt

1. Turn the oven on to 180c/350f - no need to preheat. Add the olive oil or duck fat to a baking dish and put into the oven to heat.
2. Bring a large pot of water to boil on the stove, then add bicarb soda (¼ tsp) - it will fizz a little.
3. While the water is coming to a boil, peel and chop the potatoes into approximately 2½cm (1") cubes.
4. Carefully add the cubed potatoes to the boiling water and boil for 5 mins, then drain the potatoes and allow to steam dry for a minute or two.
5. Tip potatoes back into the pot they came out of (it should have steamed dry), put the lid on and give the pot a good couple of shakes to roughen up the edges of the potato cubes.
6. Remove the baking dish with the now heated oil from the oven, carefully tip in the potatoes and turn to coat. Roast for an hour, mixing once or twice during the cooking time.
7. Once cooked, drain potatoes on paper towel. Sprinkle with herb salt and serve immediately.

Herb Salt

1. Add rock salt, finely grated lemon zest and finely chopped rosemary to a mortar and pestle and grind until a fine powder.