Mix the first 4 ingredients well. Add eggs and milk. Whisk together well to make batter. Dip chicken pieces in batter and deep fry. Drain on a pan lined with paper towels.
In a sauce pan, mix pineapple, sugar, water, vinegar and soy sauce. Bring to a boil. Mix corn starch and water together. Add to the sauce pan. Bring to a boil again. When thick, let cool for 15 minutes Add plum preserves and mix well.