In a large pot, place the red potatoes and cover them with cold water. Add a pinch of salt and bring to a boil. Simmer gently for 10–20 minutes until fork-tender. Drain and cool in an ice bath.

Set up a steamer basket over boiling water and steam the eggs for about 15 minutes. Transfer to an ice bath to stop cooking.

In a small bowl, mix mayonnaise, sour cream, and Dijon mustard until creamy. Adjust seasoning to taste.

Once potatoes are cool, cut them into bite-sized pieces. Peel and chop the hard-boiled eggs. Combine potatoes, eggs, celery, onion, dill, and chives in a large bowl.

Pour dressing over the mixture and toss gently until well coated. Season with salt and pepper to taste.