Let ground beef stand at room temperature for 10 minutes before grilling.
Preheat grill to 350° to 400° (medium-high) heat. Combine first 4 ingredients gently. Stir chopped sun-dried tomatoes and garlic into meat mixture. Shape mixture into 6 (5-inch) patties.
Grill, covered with grill lid, 4 to 5 minutes on each side or until beef is no longer pink in center. Serve on Homemade Hamburger Buns. Top each burger with refrigerated pesto, sliced goat cheese, and sliced pepperoncini salad peppers.