Crack the room temperature egg in a tall vessel, I use a pint size Mason jar. Add the rest of the ingredients except for the oil.
1 tbsp Champagne vinegar or white wine vinegar, ½ tbsp Dijon mustard, 1 tsp Lemon juice, preferably fresh, ¼ tsp Salt, 1 Egg at room temperature*
Slowly pour in the oil, being careful that the oil doesn't mix with the other ingredients.
1 cup Avocado oil (or mild flavored oil)
Put your immersion blender in the jar so that it reaches all the way to the bottom. Slowly pulse so that the ingredients on the bottom mix together first, without incorporating too much oil.
Next, start to slowly lift the blender moving it up and down in the jar. It's important to slowly incorporate the oil in with the egg so they emulsify. If you don't work slowly, they could separate or remain runny.
Beat until the mixture has thickened. Store your homemade mayo in a jar with a lid in the fridge for up to two weeks. So good.