Wash the potatoes thoroughly and cook in boiling water for about 20 minutes. Drain, rinse with cold water and peel, leave to cool. Peel and finely chop the onion. Cut potatoes into slices. Heat clarified butter in a large pan. Put the potatoes into the pan and fry them for about 10 minutes, turning them several times until crispy brown. Add the onion 2-3 minutes before the end of the cooking time and fry it. Season to taste with salt and pepper
For the dip, drain the peppers in a sieve and dice them finely. Wash parsley, shake dry, pluck leaves from the stalks and chop finely. Chop the olives finely. Clean and wash spring onions and cut into fine rings. Mix bell peppers, olives, parsley and spring onions. Season to taste with vinegar, salt, pepper and sugar
Arrange the fried potatoes and 3 slices of roast beef on plates. Spread the dip on them