Cook the potatoes, peel them, and let them cool completely.
Cook the carrots until soft. If using fresh chicken, cook it as well.
Cook eggs: Place the eggs in a saucepan, cover with water, bring to a boil and cook for 10 minutes.
Let cool: Everything should be cool before making the salad.
Dice the potatoes, carrots, chicken, eggs, gherkins, and pickled red peppers. Place in a bowl.
Add about 3/4 of the mayonnaise and the mustard, mix well and add salt and pepper to taste.
Decorate: Place the boeuf salad on a large plate or platter and smooth with a spatula. Cover nicely with the remaining mayonnaise and decorate with olives, gherkins, and pickled red peppers.
Refrigerate for a few hours before serving.