Secret ingredient packs the flavor

And here it is: The secret ingredient to chipotle chicken is mayonnaise.

The first time anyone told me that, I thought I was going to faint or laugh out loud. It sounded preposterous. But then I tasted the food and suddenly it made sense. Mayonnaise is an emulsified mixture of oil and seasonings. I always coat my food with a little olive oil, or add oil to a marinade. So mayonnaise actually makes a lot of sense.

Fast forward to a trip I took to Oaxaca, Mexico, during the February “vela” or festival season. At each neighborhood vela, the women brought out numerous platters and bowls of homemade food. My favorite was a pit-fired chicken dish that had been marinated in a thick chipotle mixture.

The minute I tasted the rich meat with a tangy, slightly smoky crust squirted with a burst of fresh lime juice, I knew that this was one souvenir I had to bring home.

I asked our guide, Mexican food expert Susana Trilling, if she could find someone who would let me come to their home and show me how to make this dish. The next day we went to the home of the village’s best cook. She had everything set out on the counter for the dish — chipotles in adobo, onions, limes, chicken thighs and mayonnaise.

As we made the marinade, I realized how smart the mayo was. You can add a lot of flavor to mayonnaise and it stays suspended. Traditional marinades tend to separate. Because the flavors are spread evenly through the marinade, the food you are flavoring gets a more intense and consistent flavor. The mayonnaise also tempers any harshness.

The chicken not only was delicious and memorable, but taught me a great cooking lesson. Today, I frequently use mayonnaise as my “secret” way to impart flavor. A classic Nantucket swordfish steak is made better slathered with mayo. And pork chops are kept flavorful and moist with a pesto mayonnaise.

But my favorite way to use it is this chipotle chicken adapted from a cook in a tiny village in Mexico.