Add unpeeled potatoes in a pot of water with 1 tsp salt. Bring to a boil and cook for about 20 minutes or until you can easily pass a fork through the center.

Meanwhile, mince onion if using. My grandma preferred onions but my mother always leaves them out. You can sauté it a little to soften the sharpness if you want.

Drain potatoes and let potatoes cool until you can hold them with your hands and peel them. Peel away skin away with a butter knife. Slice into a bowl and add onions if using.

Mix together warm broth, mustard, vinegar and oil.

Pour mixture over potatoes and stir well. Add dill/parsley, and salt and pepper to taste.

Let sit for 30 minutes to one hour to let the flavor set in. Adjust taste with more salt and pepper, or add a little more mustard and vinegar if you like. If the vinegar is too sharp add a pinch or two of sugar.

When you have it tasting the way you like it, garnish with parsley/dill and enjoy!