Place flour and corn starch in mixing bowl. Add salt, mixdry ingredients well, add cold water to form a thin batter. Add beaten egg yolks and fold in baking powder (do not stir). Let sit for five minutes and fold again (do not stir) just before using.
Prepare deep frying oil at 350-375 deg. Dip chicken chunks in batter. Deep fry 3 to 4 minutes until chicken is cooked. Remove and place on lettuce leaves on platter. Pour hot pineapple sauce over chicken and serve hot.
Bring water to a boil, add pineapple juice, add vinegar, salt, sugar and food colouring. Season to taste.Boil continuously, add corn starch (mixed with water to form thin paste) to thicken sauce. (Reduce heat after corn starch is added to avoid burning. Serve hot.
Note: A can of pineappletid-bits may be added to sauce.