Smash Burger Alfresco

Steps

1. Heat a grill to high heat and place a cast-iron griddle on the grate; let it heat for at least 20 minutes.
2. Mix pickles, mayonnaise, ketchup, adobo sauce, and 1/2 tsp salt in a bowl to make the special sauce; set aside.
3. Divide beef into eight 3-oz portions without shaping into patties.
4. Place 4 portions between sheets of parchment paper, spaced apart, and smash firmly with a mallet or skillet into thin 5-inch patties. Transfer to a baking sheet and repeat with remaining beef.
5. Wrap the buns together in foil to form a packet. Grill, turning once, until warmed through, about 1 minute.
6. Spread the special sauce on the cut sides of the buns. Top bottom buns with lettuce, onion, and tomato (if using).
7. Drizzle oil onto the hot griddle and spread evenly with a paper towel until smoking.
8. Season patties with salt, then place 4 on the griddle seasoned side down; season tops with salt.
9. Cook undisturbed until edges are browned and bottoms are crisp, about 2 minutes.
10. Flip patties, top each with a slice of cheese, and cook until melted, about 30 seconds.
11. Stack 2 patties on each prepared bun. Repeat cooking with remaining patties, scraping the griddle clean between batches.