1. In the bottom of a tall (yet thin) measuring cup or jug crack the whole egg, add the garlic and salt.
2. Pour in olive oil to make up one cup (a little more if you want a little thinner Aioli - the actual amount of olive oil required will depend on the size of egg.
3. Push the handheld blender to the bottom of the jug and turn on the blender. Slowly lift the blender to the top of the oil. Repeat two or three times, or until smooth. Remove blender, shaking off excess.
4. Add lemon juice and stir in using a spoon.
5. Taste and add more lemon juice and salt as required.