BARBEQUE with Coca Cola

1 (3-4 lb.) roast
1 onion, sliced
1 (14 oz.) bottle catsup
1 (12 oz.) container classic Coca Cola

Place roast in small roasting pan. 
Pour catsup and Coca Cola on top. 
Place sliced onion on top and cover. 
Cook in 325 degree oven for 3 1/2 hours. 
Do not place roast on rack in pan. 
Do not salt, pepper or brown roast.