Beef salad (Bernese style)

Ingredients

• 1 carrot
• 100 g knob celery
• 1 shallot
• 100 g leek
• 900 g beef for boiling (boiling meat)
• 1 / 2 ts peppercorns
• 1 bay leaf
• 250 ml beef broth
• 5 hard-boiled eggs
• 400 g tomatoes
• 2 pickles
• 1 onion
• 4 tbs sunflower oil
• 2 tbs white wine vinegar
• 2 ts mustard
• salt, pepper