Step 1

Saute the onion in a small skillet with 1 teaspoon of the oil until soft, 3 to 4 minutes.

Step 2

Transfer to the blender then add the remaining oil, mayo, vinegar, mustard, salt and pepper.

Step 3

Then add the chopped jalapeno, cilantro and garlic and blend on high speed until the sauce is smooth and creamy, about 30 seconds.