Kev loves garlic mayo and that has spurred me on to this recipe. The science behind mayo is basically the eggs need an acid to bind with the oil. The original recipe I found used lemon juice as the acid. Then one day disaster struck and I had no lemons! So thinking on my feet vinegar was added and it worked just as well. The thing I love about this mayo is what you can add to it. Add tomato sauce and Worcester sauce and you have prawn cocktail sauce to name just one use.

2 egg yolks (room temperature)
2 tablespoons vinegar or lemon (I used white vinegar)
200ml oil (I use our own olive oil but I think you can use any)
Salt to taste
1 teaspoon mustard (I used Dijon but it works as well with English mustard)

I used a hand blender to mix as I find this easier but you can use a food processer or a hand whisk.

Place the egg yolks and vinegar into the mixing jug and blitz until mixed.
Add a tablespoon of oil and blitz again. 
(You must add the oil gradually and I found this method works. It may take a little longer but the end result is worth it!

Keep adding the oil a tablespoon at a time and blitzing making sure all the previous oil has mixed in.
When all the oil has been added you add the mustard and salt to your taste.
That is all there is to it. Homemade can't beat it!