For the Chinese ravioli with pak choi, first prepare the dough. To do this, mix flour, eggs and oil in a food processor and add enough water to make a kneadable pasta dough. Form a ball from the finished dough and let it rest under a damp tea towel for 1 hour.
For the filling, brown the beef in oil. Mix the sautéed beef with ginger, leek, rice vinegar, soy sauce, tomato and the sesame oil and salt well and let it sit for 10 minutes at a moderate temperature.
Portion the dough, roll it into a 2, 5 cm diameter roll and cut it evenly into pieces. Roll out the dough flakes into pieces 8 cm in diameter. Place a heaping teaspoon of the filling in the center of the dough flakes, fold the flakes together and press the slightly moistened edge together thoroughly. Trim the edge with a pastry wheel if desired.
In a large saucepan, bring salted water to a boil and drop in the ravioli. The ravioli are done when they rise to the surface. Lift out of the water with a slotted spoon and drain well.
For the pak choi, mix all the ingredients for the sauce. Remove the outer leaves from the pak choi and fry in oil in a wok (or frying pan). Pour the sauce over it and let it simmer at low temperature for 8 to 10 minutes with the lid closed.
Serve the Chinese ravioli with pak choi and season with soy sauce.