Sift the flour into a bowl with the salt and make a well in the middle. Add 100ml of water to the milk and mix. Break the eggs into the well and whisk slowly, while adding the milk and water mixture. Whisk until smooth and then set the batter aside to rest for 30 mins, before whisking in the melted butter.
Heat the pan over a medium heat and lightly grease it with melted butter. Using a ladle, pour about 2 tbsp of batter into the pan and swirl it around so the bottom of the pan is evenly coated. Cook the pancake on both sides until golden and then slide it out of the pan and stack on a warm plate with baking parchment in between. Repeat to use up all the batter, then keep the pancakes warm while you make the sauce.
Put the caster sugar into a non-stick frying pan over a low-medium heat. Allow the sugar to melt slowly without stirring, until it turns to a caramel liquid. Immediately slide the pan off the heat and add the orange juice, taking care as it may spit as it hits the hot caramel. Add the orange zest, lemon juice and Grand Marnier and return the pan to a low heat to re-melt the caramel into the liquid. Add the butter to the sauce and bring to the boil. Simmer gently until glossy and reduced slightly to a syrupy consistency.
To serve, fold the warm pancakes into quarters and arrange in a dish. Pour over the orange sauce and top with a generous helping of Trewithen Dairy Clotted Cream – delicious!