Place whole unpeeled potatoes into a large soup pot and add enough cold water to cover.
Place over high heat and bring to a boil; reduce the heat to low and simmer until potatoes are tender, about 15 minutes depending on their size.
Drain potatoes and sprinkle generously with salt and pepper. Allow the potatoes to completely chill. (You can make this step ahead and keep them refrigerated for up to 5 days).
While the potatoes cool, in a small bowl mix the remaining ingredients.
Once the potatoes are cool, you can either peel if desired, or chop them with the skin on. Cut into small bite size cubes.
Toss the potatoes with the mustard-yogurt sauce; taste and adjust seasoning if needed.
Serve cold and enjoy!
Baby new potatoes: New potatoes don't refer to a specific variety, but just mean young potatoes. They hold their shape well and have a creamy texture after cooking. Some options for new potatoes are baby red potatoes, baby Yukon golds, or baby yellow potatoes.
Greek yogurt: We suggest using full fat yogurt for the most creamy texture.
Dijon mustard: You can substitute with yellow mustard or spicy brown mustard, but each one will have a different flavor. Choose your favorite.
Shallots: If you don't have shallots, substitute with sweet onion or red onion.
Choosing potatoes: Try to choose small, evenly sized potatoes. This will help them cook evenly.
Cooking tip: After the water comes to a boil, simmer the potatoes instead of boiling. This also helps them cook more evenly.