What you'll need:
1 large organic free range egg
1 tsp Dijon mustard
1 tbsp lemon juice
1 cup light olive oil
1/2 tsp sea salt
Also a stick blender and a tall thin beaker or glass jar which fits the head of the blender all the way to the bottom. Most stick blenders come with this included in the box.
1. Crack the egg into the beaker or jar. Some recipes call for the egg to be fridge fresh, some call for all the ingredients being room temperature. Mine were bought fresh from the shop and endured the crisp 40 minute walk home so were more on the cold side of room temperature.
2. Add the teaspoon of Dijon mustard, which should be at roughly the same temperature as the egg.
3. Add the freshly squeezed lemon juice.
4. And then the oil which should bring the total of the ingredients to one cup of liquid or eight fluid ounces.
5. Leave the ingredients to settle in the container. When you first add the oil it will agitate the other ingredients which can hinder the emulsification process. I left mine for around five minutes.
6. Put the stick blender all the way into the liquid, still switched off, and push down until it touches the bottom of the container. The comes the scary bit - switch the blender on! For the first 30 seconds you will need to hold the blender to the bottom of the container so it doesn't move. You'll see the mixture turn white at the bottom (your homemade mayonnaise!) and begin to slowly move up the sides and further up into the oil. Once nearly all the oil has transformed to mayonnaise you can move the blender around a little, up and down and tilting it. And... That... Is... It.
Done! Thick and creamy fresh mayonnaise with none of the gross hydrogenated oils or added E numbers you find in the shop-bought version. It should last around 1 week kept in a tightly covered glass jar and can be flavoured in the same way as any mayo, add garlic and you can have homemade aioli or add capers, anchovy and tuna for an Italian tonnato sauce.