1. Preheat grill to medium high. Clean grates and then brush with oil. Place Vermont Castings cast iron griddle with the flat side up onto the grill directly over the burners on one side.
2. Divide the ground brisket into 4 equal parts and roll each piece into a ball.
3. Place Vermont Castings Lonestar Beef Brisket Rub in a dish and roll each ball in the rub until well covered. Set aside. Discard any remaining rub.
4. In a small bowl, toss shisito peppers in oil and salt until well coated. Place shisitos on griddle and cook with the lid closed, fl ipping frequently, until soft and charred, 4-6 minutes. Remove and set aside.
5. Place meat on the griddle, leaving space between each ball, and flatten to -inch thickness (1.25 cm) with a Vermont Castings Cast Iron BBQ Grill Press.
6. Cook for 2-3 minutes, with the lid closed, until the sides of the burgers start to brown. Flip burgers and cook until they reach an internal temperature of 160˚F (70˚C), 2-3 minutes longer.
7. Toast buns on the opposite side of the grill until golden brown. Place cooked patties on the buns with lettuce, tomato, red onion and top with charred shisito peppers.