I had this at Bennigan's one night, and I realized I had to learn how to make it at home. I think it came with the southwestern eggrolls. I don't even remember the appetizer, just the amazing dipping sauce.
1 cup mayonnaise
4 tbs fire roasted tomato salsa
8.25 oz can drained crushed pineapple
2 tbs pineapple juice (if you buy the crushed pineapple packed in juice, you can just use the juice from there instead of buying a whole thing just for 2 tbs)
2 1/2 tbs sugar
1. Combine all ingredients and mix on medium for two minutes
2. Chill in the fridge for an hour