2 (16 oz.) cans whole green beans
1/4 c. finely chopped onion
2 tbsp. salad vinegar
1 tbsp. vegetable oil
1/4 tsp. salt
1/2 tsp. pepper

Drain green beans, reserving 1 cup liquid. Place beans in a small bowl. Combine bean liquid, onion, and remaining ingredients, pour over beans, tossing gently. Cover and chill at least 2 hours.