Name: Spanish Burger with Pickled Shallots
Cook time: P0Y0M0DT1H5M0.000S
Total time: P0Y0M0DT1H30M0.000S
Yield: 4 Spanish burgers
Ingredients: 1 stick unsalted butter; 1 tablespoon harissa; 2 cloves garlic, smashed; 3/4 cup sherry vinegar; 1 tablespoon sugar; Kosher salt; Pinch of saffron; 2 large shallots, thinly sliced; 1/4 cup mayonnaise; 1 teaspoon harissa; 1/4 teaspoon smoked paprika; 2 jarred piquillo peppers (or 1 roasted red pepper),patted dry; 1 anchovy fillet; Juice of 1/2 lemon; Kosher salt and freshly ground pepper; 1/2 cup canola oil; 4 thin slices prosciutto di Parma; 1 1/4 pounds ground beef chuck; Kosher salt and freshly ground pepper; 1 tablespoon canola oil; 4 slices fontina cheese; 4 soft sesame buns, lightly toasted; Baby arugula, for topping

Directions

Make the spiced butter: Melt the butter over low heat in a small saucepan. Add the harissa and garlic and cook 1 minute. Remove from the heat, cover and let sit 1 hour to allow the flavors to meld.
Make the pickled saffron shallots: Bring the vinegar, sugar, 1 teaspoon salt and the saffron to a boil in a small saucepan set over medium heat; remove from the heat and let cool 10 minutes. Put the shallots in a small bowl, pour the vinegar mixture over them, cover and refrigerate at least 30 minutes and up to 24 hours.
Make the aïoli: Combine the mayonnaise, harissa, smoked paprika, piquillo peppers, anchovy and lemon juice in a blender and blend until smooth; season with salt and pepper. Cover and refrigerate at least 30 minutes to allow the flavors to meld.
Make the crispy prosciutto: Heat the canola oil in a small sauté pan over medium heat until it shimmers. Add 1 slice of the prosciutto at a time to the pan and cook until just crisp. Drain on a plate lined with paper towels.
Make the burgers: Put the ground beef in a large bowl and mix in some salt and pepper. Divide into 4 equal patties.
Heat a cast-iron pan over high heat until smoking. Add the canola oil and burgers and cook until the bottoms are golden brown and a crust has formed, about 4 minutes. Flip over and begin brushing with the spiced butter. Cook until the bottoms are golden brown and the meat is cooked to medium, about 4 more minutes. Top the burgers with the fontina, add a little water to the pan, cover quickly and cook until the cheese is completely melted, about 1 minute.
Spread some aïoli on the top and bottom buns. Place a burger on each bottom bun; top with pickled shallots, followed by a slice of crispy prosciutto and arugula. Add the top buns and serve.

Cook’s Note

Resist the urge to flatten the burgers as they cook. You’ll end up with a dense, dry hockey puck. Be sure to flip the patties only once — and don’t touch them until a crust has formed on the bottom. You’ll also want to cook beef burgers until medium rare to medium (about 145˚ F); this will take 7 to 8 minutes total.