Chop the meat finely and with a knife, making small cubes. In a bowl, put the mayonnaise, the egg yolk, the mustard, the perrins sauce, and a spoonful of olive oil. Mix well and add salt and pepper. Add the chopped spring onion, parsley, pickles and chopped capers.
Then add the chopped beef fillet. Mix it, taste and add salt as necessary.
Place the tartar in the middle of a plate with the help of a plate ring. Accompany it with slices of toasted bread, some sprouts and red onion in julienne.