Add the potatoes to a large pot and cover with cold water. Place on the stove and bring the water to a boil (this goes faster if you place the lid on top until the water starts boiling. Salt the water generously with a small palmful.
Allow the potatoes to boil until they are fork tender. There should be a slight resistance when you prick them with a fork but they shouldn´t completely fall apart. This should take around 25-30 minutes depending on the size of your potatoes. as of 20 minutes, start checking them every 5 minutes until they are done.
Remove the potato skins: Once the potatoes are finished cooking, drain and rinse them in cold water. While the potatoes are still hot, use a clean kitchen towel to cover your hands and rub off the skins from the potatoes.
Cut the potatoes in 1/4 inch slices and add them to a large bowl.
Make the marinade: to a medium saucepan, add the water and vegetable bouillon cube (or broth), vinegar, dijon mustard, salt, sugar, and minced onion. Bring to a boil and remove from the heat.
Pour the marinade over the potatoes and cover the bowl (I like doing this with a baking sheet). Let sit for at least 1 hour, stirring once halfway and re-covering.
Add the neutral oil , cucumber, and chives. Let sit in the fridge for at least 2 hours or ideally overnight. Enjoy!
