Preheat grill. Roast jalape�o on the grill until charred. Remove from grill and place in a resealable plastic bag to steam off the skins. After 10 minutes remove and peel skins and remove seeds. Chop finely.
Chop bacon and combine with 1/2 of the jalapenos, and beef. Divide into 6 parts and form into patties.
Meanwhile combine the other half of the jalapenos with the mayonnaise, olive oil, and cilantro, season with salt and pepper.
Grill burgers on hot grill to desired doneness. Remove from grill, top with mayonnaise sauce, avocados and onions on hamburger buns.