If using regular potatoes, chop into equal-sized ones.
Boil potatoes till it's just cooked. Careful not to overcook if you have sliced or chopped small.
In a blender or food processor, add in garlic, cilantro, olive oil, and pulse till these are finely minced.
Now add little water and dijon mustard and blend for just 30 - 40 seconds.
Season with salt and pepper.
Sprinkle some chopped celery stalks and chopped green onions.
Give a nice stir and serve.
Notes
You can also pressure cook the baby potatoes just for 1 whistle and then chop it into quarters.If using regular potatoes then chop first and boil in salt water till cooked.