Hard-boil the eggs in a pot of water for about 10 minutes. Once cooked, transfer them to cold water to cool quickly. Then peel and finely dice.
Preparing the radishes:
Thoroughly wash the radishes, peel them, and thinly slice them.
Mixing the ingredients:
In a large bowl, combine the mayonnaise, sour cream, salt, pepper, vinegar, and mustard. Add the sliced radishes and mix thoroughly.
Adding the eggs:
Gently fold the sliced eggs into the prepared mixture.
Cover the bowl and refrigerate the salad for at least 3 hours to allow the flavors to meld.
Once chilled, taste the salad and season it with additional salt, pepper, or mustard to your liking.