Pepper & Onion Pretzel Burgers

If you’re grilling, preheat your grill to maintain a temperature of 450-500°F. Oil the grill grates. Place an oven rack in the center of the oven, then preheat to 450°F. Wash and dry the fresh produce. Cut off and discard the stems of the sweet peppers; remove and discard the cores, then thinly slice lengthwise. Peel and thinly slice the onion. Large dice the potatoes. Thinly slice the piquillo peppers. Thinly slice the cheese. Halve the buns. Peel and finely chop the garlic; using the flat side of your knife, smash until it resembles a paste (or use a zester). In a bowl, combine the mayonnaise and up to half the garlic paste. Season with salt and pepper. 

Line a sheet pan with aluminum foil. Place the diced potatoes on the prepared sheet pan. Drizzle with olive oil and season with salt and pepper; toss to coat. Arrange in an even layer. Roast 24 to 26 minutes, or until tender when pierced with a fork. Remove from the oven. 

While the potatoes roast, in a large pan (nonstick, if you have one), heat 2 teaspoons of olive oil on medium-high until hot. Add the sliced sweet peppers and onion and remaining garlic paste; season with salt and pepper. Cook, stirring frequently, 8 to 9 minutes, or until softened. Add the sliced piquillo peppers and vinegar (carefully, as the liquid may splatter); cook, stirring frequently, 30 seconds to 1 minute, or until combined. Transfer to a bowl; cover with aluminum foil to keep warm. 

In a medium bowl, combine the beef, spice blend, and breadcrumbs; season with salt and pepper. Gently mix to combine. Using your hands, form the mixture into four 1/2-inch-thick patties; transfer to a plate. 

STOVE: Wipe out the pan used to cook the peppers and onions. In the same pan, heat 2 teaspoons of olive oil on medium-high until hot. Add the patties and cook 4 to 5 minutes on the first side, or until browned. Flip the patties (carefully, as the oil may splatter). Evenly top with the sliced cheese. Loosely cover the pan with aluminum foil and cook 4 to 5 minutes, or until the cheese is melted and the patties are cooked through. Leaving any browned bits (or fond) in the pan, transfer to a plate.
GRILL: Lightly oil the patties. Grill 6 to 7 minutes on the first side, or until browned. Flip and continue to grill 4 minutes. Evenly top with the sliced cheese. Continue to grill 2 to 3 minutes, or until the cheese is melted and the patties are cooked through. Transfer to a plate. 

STOVE: Working in batches if necessary, add the buns, cut side down to the pan of reserved fond. Toast on medium-high, 1 to 2 minutes, or until lightly browned. Transfer to a work surface.
GRILL: Grill the buns, cut side down, 1 to 2 minutes, or until lightly browned. Transfer to a work surface.

Assemble the burgers using the toasted buns, cooked patties, and cooked peppers and onions. Serve the burgers with the roasted potatoes and aioli on the side. Enjoy!