Put the beef to boil in a pot with the bay leaf, salt and allspice. After it boils, remove the tendons and membranes and cut it into small cubes.
Save the broth in which you've boiled the meat (if necessary you can strain it).
Chop the onion finely and braise it briefly, add the kritharaki.
Pour the broth into the onions and pasta. Shortly after it comes to a boil, season and add the meat.
A little before the dish is completely ready, add the tomato paste. Boil another 5-10 min. and leave the pasta to absorb all of the liquid.