Generously grease a 12 hole muffin pan with oil. Sift flour and salt into a mixing bowl. Make a well in the centre. In a separate jug whisk together eggs, milk and water. Pour into the flour a little at a time, beating using electric beaters until batter is smooth. Transfer batter to jug. Allow to stand for 30 minutes. Preheat oven to 200°C (fan bake). Place greased muffin pan in the heated oven for 2 minutes. Remove and pour the batter into the muffin holes. Bake for 10-15 minutes until yorkshire puddings are puffed and golden.