In a food processor, combine all ingredients for marinade with the exception of the green onions. Season with salt and pepper.
Add the green onions and place into a non-reactive marinating dish.
Place ground beef in a bowl and season with salt & pepper.
Form into 8-ounce patties.
Add patties to marinade and let sit for 20 minutes, flipping once half way through.
While patties marinate, prepare mayonnaise according to recipe below.
Preheat grill to 500 degrees Fahrenheit.
Place pimento chips in a smoker box and position the box over a burner or on top of burning coals. (For a more traditional flavor, make a bed of chips on the coals and lay the food on top of the chips. This allows the food to be bathed in the smoke and absorb more of the flavor.)
As with most other woods, soaking pimento wood chips is not necessary. It does not make chips burn more slowly, it just delays the burning until they dry out.
Sear over direct heat, brushing each side once with marinade, till caramelized or seared on both sides.
Rest in cooler area of grill till cooked to desired doneness.
Serve with mayonnaise, onion slices, tomato slices, and lettuce.
Combine mayonnaise and chipotle chilies in adobo, and refrigerate for later use.