Ingredients:

1 bunch large scallions [about 4 ounces, 110g].
1 small onion [2 ounces, 55g], peeled and quartered
1 medium tomato [about 5 ounces, 140g], quartered
3 large eggs
Salt and freshly ground black pepper
1 tablespoon vegetable oil


Method:

1/2 pound [230g] Japanese buckwheat noodles (soba), available at some supermarkets and most oriental food stores. Cook according to package instructions until tender. (Alternatively you may like to make your won noodles and he recipe and method is at the end of this instruction.)
Slice the scallions  thinly [2mm]. Set aside.
Chop the onion coarsely. Set aside.
Chop the tomato.
Beat the eggs in a bowl with salt and pepper to taste. Heat 1 teaspoon oil in a nonstick 10-inch [25 cm] skillet over medium-high heat, add the eggs, and cook, tilting the skillet to let the uncooked egg flow underneath the omelet, until set, 2 to 3 minutes. Invert onto a cutting board and cut into 1/4-inch [6mm] strips.
Cook the onion in the remaining 2 teaspoons oil in the skillet over moderate heat, stirring, until browned, 3 to 5 minutes. Add the scallions and tomato and cook until softened, about 3 minutes.
Add the noodles and egg strips and toss carefully over low heat until heated through.



Option: Dough for making your own pasta.

1 cup all-purpose flour [5 ounces, 140g]
1/4 cup buckwheat flour [2 ounces, 40g]
1 teaspoon salt
2 large eggs, lightly beaten
1 tablespoon water
All-purpose flour, for dusting
To make the dough, combine the flours and salt in the work bowl of a food processor fitted with the metal blade. With the motor running add the eggs and water through the feed tube and process until the dough forms a ball. Dust the ball with flour.
Quarter the dough, dust with flour, and wrap 3 pieces in plastic wrap to prevent drying out. Roll out the remaining piece with a pasta machine according to the manufacturer's instructions, down to the second lowest setting, dusting with flour occasionally to prevent sticking. Lay the sheet on a rack or a lightly floured surface until dry but not brittle, about 10 minutes, turning once. Meanwhile, roll out the remaining dough and dry in the same manner.
Use the finest cutter to cut the dough into noodles. Spread the noodles on a clean towel to dry for 15 minutes.
Cook the noodles in a saucepan of boiling water until just tender, about 1 minute. Drain and rinse under cold water.