Pickled Shrimp
["2 lb. raw, peeled and deveined shrimp (41 to 50 count or larger)", "2 medium white or purple onions, sliced into rings", "1 c. vegetable oil", "1 1/2 c. white vinegar", "1/2 c. sugar", "1 1/2 tsp. salt", "1 1/2 tsp. celery seed", "4 Tbsp. capers with juice"]
["Place shrimp in boiling salted water; reduce heat and simmer for 3 to 5 minutes.", "Shrimp are done when they are pink and tender; drain and rinse with cold water, then chill."]
["shrimp", "white", "vegetable oil", "white vinegar", "sugar", "salt", "celery", "capers"]