Combine pork strips, soy sauce, sherry, sugar and ginger in a bowl
Mix well and allow to marinade in the refrigerator for at least 3 hours or overnight
In another bowl, combine water, cornstarch and chicken bouillon and mix well
Melt butter in large flat frying pan on medium-high heat
Pour eggs in frying pan and swish pan around so that the eggs evenly coat bottom of pan
Cook eggs for about 3 minutes or until done, turning once
Remove eggs from pan, place on plate and cut into thin strips
Add pork and marinade to pan and cook on medium high heat while stirring until done (about 4 minutes)
Add onion and cook for about 2 minutes
Add cabbage, bean sprouts and water chestnuts and cook for about 2 minutes or until just crisp-tender, stirring often
Add cornstarch mixture and cook and stir until thickened
Add eggs and stir to combine all ingredients
Spread one tsp
of hoisin sauce on each tortilla, top with about 1/2 cup pork mixture, roll up tortilla and serve