"Nothing is more all-American than burgers on the grill. Sliders are burgers’ new-century party incarnation. Cooking them over fire in muffin tins is so much easier than flipping them all individually and lining the tins with caramelized onions imparts the vegetables’ sweet, rich flavor to the meat while they cook. Sheer genius, if we do say so ourselves. We like to serve them on our own buttermilk rolls because, really, what is better than homemade bread in any form? (You can buy rolls, but they won’t be as good.) Pass these babies with a few other appetizers, and you’ve got yourself a party."
Muffin tins with 4-ounce cups (or disposable aluminum muffin tins), enough for 18 sliders
For Caramelized Onions:
2 tablespoons olive oil
3 large sweet onions, sliced
1 teaspoon salt
1 tablespoon water
For Seasoned Salt:
3/4 cup kosher salt
2 tablespoons sugar
2 tablespoons paprika
1 tablespoon celery salt
1 tablespoon garlic powder
1 tablespoon onion powder
1 teaspoon ground turmeric
1/2 teaspoon dried oregano
1/2 teaspoon ground thyme
1/8 teaspoon ground cinnamon
21/2 pounds freshly ground chuck, 80% lean
9 slices deli-style American cheese, quartered
647 Secret Sauce, recipe below
1 16-ounce jar dill pickle chips
647 Secret Sauce:
1/4 cup (60 g) mayonnaise
1/4 cup (35 g) finely chopped dill pickles, drained well
2 tablespoons (30 ml) Dijon or spicy brown mustard
2 tablespoons (30 ml) ketchup
1/2 teaspoon (2 g) sugar, or more to taste
Freshly cracked black pepper, to taste
Prepare your smoker or kettle grill and bring temperature to 300°F.
To Caramelize the Onions: Heat the olive oil in a large, nonstick sauté pan over medium-high heat. Add the onions and salt and cook, stirring often, until onions soften and just start to brown. Reduce heat to medium-low and cook, stirring occasionally, until onions collapse completely and turn a rich, jammy brown, about 30 minutes. When onions are nearly done, add the water and stir, scraping the browned bits on the bottom of the pan into the onions. Set aside to cool.
To Make the Seasoned Salt: In a bowl, mix all ingredients together, then grind in a spice grinder.
To Make 647 Secret Sauce: In a bowl, mix all ingredients together. Cover and chill. Before serving, taste to correct seasoning with sugar and pepper. The sauce will keep, covered tightly and refrigerated, for up to 2 months.
To Make the Burgers: Divide the ground beef into 18 golf ball–sized rounds (about 2½ounces each). Spread about¼cup seasoned salt on a plate and roll the balls lightly in the seasoned salt to coat.
Spread 1 tablespoon of caramelized onions in the bottom of each muffin cup (A). Place 1 meatball on top of the onion in each cup and press down with your fingers to form into an even burger (B). Put the muffin tins on the grill grate, close the lid, and cook for 30 minutes. Remove the muffin tins, overlap 2 quarter-slices of American cheese on each burger, and tent the muffin tins with foil (C).
If your slider rolls are not fresh from the oven, wrap in foil and place on the smoker for 5 minutes, or microwave for 20 seconds. You want the slider rolls to be soft and squishy inside.
To serve, use tongs to transfer the burgers from the tins to the slider rolls. Then, with the tongs, pick up some of the remaining onions and place on top of the burger. Garnish with a generous schmear of 647 Secret Sauce and pickle chips.