Steak tartar

250 gr of beef tenderloin. Other pieces of meat can be used but with sirloin it is spectacular because it is a super tender meat which is the important thing since it is not going to be cooked. Its price is high but it is well worth it. 1/2 small spring onion. 1 tablespoon of capers or tápenas. 1 dessert spoonful of mustard in grain or to the old one. 1/2 teaspoon of Perrins sauce. A few drops of Tabasco, just 4 or 5. 1 egg yolk M. 40 ml of extra virgin olive oil. Salt and freshly ground black pepper. Fresh chives for garnish and I also recommend you to have some small toasts to eat it.

Mix everything together and serve