Instructions

1. Pour 50ml (1/4 cup) of olive oil into a jar or mixing bowl. Add the egg, mustard powder and salt and begin to blend with a stick blender.
2. Once those ingredients have mixed, slowly drizzle in the rest of the olive oil while the blender is still running. The slower you do this the more likely it is that the egg and oil will emulsify correctly.
3. Once all the olive oil has been incorporated, add the lemon juice to your taste.
4. Keep in a lidded jar in the fridge for up to one week.