pork with hoisin sauce

ngredients:
3/4 pound boneless pork
Marinade:
2 teaspoons Chinese rice wine or dry sherry
1 teaspoon soy sauce
Pinch of salt and pepper
Sauce:
2 tablespoons hoisin sauce
1 teaspoon soy sauce
4 tablespoons water or chicken broth
Other:
3 1/2 tablespoons oil for stir-frying, or as needed
2 slices ginger