The Case of the Mysterious Corn-and-Bean Salad

HELP!!

While visiting with family last week I had the most delicious corn-and-bean salad I've ever tasted. After just one bite, I was hooked. I couldn't help but cut my way back into line again for seconds (and thirds, maybe?). The following day, I was even caught sneaking spoonfuls of the leftovers...more than once. Oops. 

Now, as head-over-heels as I was about this tasty side dish, I can't believe I left without getting the recipe! What was I thinking??

I've been searching online all week for it, but I just can't seem to find an exact replica of the recipe.

Here's what I'm pretty sure I was tasting:

-canned black beans
-canned corn kernels
-canned kidney beans
-diced scallions
-(maybe) some diced onions
-and some delicious dressing/marinade that slightly resembled Italian dressing

And here are the imposters I've come across so far:

-Cooking Light's All-Purpose Southwestern Corn and Black Bean Salad. Mmm this recipe includes lime juice and honey in the dressing, and it offers great suggestions for turning it into a main-dish salad or a dip!

-RealSimple's Three Bean Salad. This one actually looks pretty similar, and I like the addition of chickpeas!

-All You's Corn and Black Bean Salad. This recipe's really close too! I could just switch the roasted red peppers out for kidney beans. Maybe their cider vinegar is the secret ingredient I'm missing!

-Southern Living's Black Bean Salad. This picture looks almost identical! Just hold the jalapeños and tomatoes, and add in the kidney beans. I like the fresh corn!

Anyone have any leads for me, or maybe a favorite recipe of your own that I might love just as much?