In a mixing bowl, combine the soy sauce, brown sugar, can of pineapple tidbits (with the juice), lemon juice, ginger and garlic. whisk until brown sugar is dissolved. pour half of the marinade into a tupperware container. make sure all the pieces of pineapple go into that container with the marinade. cover with a lid and put in the refrigerator.
pour the other half of the marinade into a large ziploc bag. add the chicken breasts into the ziploc bag as well. seal and allow the chicken to marinate for at least an hour, preferably overnight.
preheat the oven to 375 degrees.
combine the cornstarch and water in a small bowl. set aside.
remove the reserved tupperware container with the marinade from the refrigerator. pour into a saucepan and allow to come to a bubble. once the sauce starts to boil, whisk the cornstarch mixture into the sauce. allow to thicken. remove from heat. set aside.
while the sauce is heating, preheat a large oven proof skillet. i used a 14 inch cast iron. like this one here. add the oil. once hot, remove the chicken from the marinade, shake off excess and carefully lay into the skillet (discard the bag of marinade). allow to sear on that side for about 3 minutes, and flip. pour the reserved thickened sauce over the chicken breasts. immediately place the skillet in the oven and bake in the preheated oven for 15 - 20 minutes or until chicken is cooked through.