Place the chicken in a gallon size plastic bag. Pour half of the teriyaki sauce in the bag and massage the bag until evenly coated. Marinate in the fridge for several hours or overnight.

Grill the chicken over medium to medium high heat for 4 to 6 minutes per side, depending on thickness of the chicken. During the last few minutes, grill the pineapple slices and brush both sides of the chicken with the remaining teriyaki sauce.

Once the chicken is cooked turn the grill off. Add a slice of cheese, some cooked bacon crumbles, and one slice of pineapple on each chicken breast.

Close the grill for a few minutes, until cheese is melted.

Serve with the remaining grilled pineapple slices and more teriyaki sauce for dipping if desired.