Sweet and Sour Chicken

1 pound chicken, cubed and cooked
1 bag frozen veggies
1 -8oz can pineapple, juice reserved
2 Tbls. cornstarch
1/3 c. apple cider vinegar
1/3 c. brown sugar packed
1/2 tsp. pepper
1/4 c. Chinese sweet and sour sauce
cooked rice

Drain pineapple reserving juice. Combine cornstarch, vinegar, sugar, pepper, sweet and sour sauce and pineapple juice. Put 3 Tbls butter in skillet, cook veggies til tender, than cook chicken in a couple Tbls of butter. Add sauce and cook 5 minutes more til bubbly. Add veggies and pineapple , serve over rice.