Sweet 'n' Sour Stew

2 pounds beef chuck, cut into 1 1/2-inch cubes
3 tablespoons all-purpose flour
1 tablespoon vegetable oil
1 (1 pound) can tomatoes
2 medium onions, sliced
1 teaspoon celery salt
1 teaspoon salt
1/4 teaspoon pepper
1/3 cup vinegar
1/3 cup Grandma