Ground pork is becoming more common in the meat case. You can also ask your butcher to grind it. Usually the lean-to-fat ratio is similar to ground chuck. We find French hamburger buns at Publix grocery stores.
Coat cold cooking grate of grill with cooking spray, and place on grill. Preheat grill to 350° to 400°(medium-high) heat.
Gently combine pork and reserved 2 Tbsp. mayonnaise mixture until blended, using hands. Shape into 4 (4-inch-wide, 1-inch-thick) patties.
Stir together butter and next 3 ingredients in a small bowl until well blended. Sprinkle each patty with about 2 Tbsp. pecan mixture (about 1 Tbsp. on each side), gently pressing to adhere.
Grill pecan-covered pork patties, covered with grill lid, over 350° to 400° (medium-high) heat 6 to 8 minutes on each side or until a meat thermometer inserted into centers registers 155°.
Grill buns, cut sides down, 1 to 2 minutes or until lightly toasted. Serve burgers on buns with lettuce and Dried Apricot-Chipotle Mayonnaise.