1) If you dont have wasabi paste, you can skip it.
2)Add 1 tsp wasabi powder with some water to form a paste. You can add that instead of wasabi paste.
3)You can add garlic instead of wasabi.
4)You can add chilli flakes if you need some spicyness.
5)Use flavourless oil for best results.
6)Using immersion blender is best. you can use hand blender or food processor too.
7)if you dont have mustard sauce use mustard powder.
8)Vinegar can be used instead of lemon juice.
9)Use room temparature egg for best result.
10)This mayonnaise can be stored in fridge for a week.