Wipe the kombu with a damp cloth, then place in a saucepan with water. When the water comes to a boil remove kombu from water. Sprinkle in the bonito flakes and remove saucepan from heat. As soon as the bonito flakes start to sink, strain stock.
Combine foie gras, eggs, chicken stock, and salt and pepper in a mixer fitted with a paddle attachment. Mix until fine then strain into 4 small serving dishes. Steam in dishes for 10 minutes.
In a small saute pan, sear the duck breast, skin side down for 4 minutes. Remove from the pan, let cool slightly, and slice thinly. Coat both sides of the duck slices with cornstarch.
In a saucepan, combine dashi broth, mirin, light soy sauce, soy sauce, and sugar and bring to boil. Using cooking chopsticks or tongs, lightly cook the duck breast in boiling teriyaki sauce, maybe 5 seconds per slice. Place 2 or 3 pieces of duck on top of each of the steamed foie gras dishes.
Thicken the teriyaki sauce with cornstarch and water, if necessary, and then pour over duck. Finish with wasabi.