Mince the cured ham in a skillet. Remove from the heat and set aside. Rig for deep frying, heating the oil to 350 degrees.
Mix the ginger, soy sauce, fish sauce, and black pepper in a large bowl.
Cut the bell peppers, celery, and bok choy into strings; mix them into the bowl, along with the chopped parsley or cilantro, onion, and water chestnuts.
Lightly beat the eggs and stir them in. Add the crabmeat and minced ham. Mix everything well, then put about 1 tbsp of the mixture on each egg roll skin. Fold the skins over, roll, and seal lightly with a little water.
Deep-fry a few at a time until the rolls are slightly browned. Do not overcook. Drain on brown bags. Serve hot, along with a dipping sauce or two.