Sweet and Sour Steak

1 - 1-1/2 lbs. petite sirloin, thinly sliced while it is still partially frozen
bell pepper, onion, or carrot--thinly sliced as desired
1 can pineapple tidbits
2 Tbl. cornstarch
1-1/2 Tbl. soy sauce
1/4 cup brown sugar
3 Tbl. vinegar
Sliced tomatoes, optional

In large skillet (not non-stick) saute meat and desired veggies in a bit of oil.  Meanwhile, in small bowl, measure juice from can of tidbits.  You need pineapple juice + water = 1 cup.  Whisk cornstarch, soy sauce, brown sugar, and vinegar together with pineapple juice in small bowl.  Add mixture to cooked meat & veggies.  Simmer 'til sauce is thickened.  (Add more pineapple juice/water as needed to desired thickness.)  Add pineapple tidbits and sliced tomatoes and stir only a bit. Serve over rice.