Spanish Burger with Pickled Shallots

Deselect All

For the spiced butter: 

1 stick unsalted butter

1 tablespoon harissa (chile paste) 

2 cloves garlic, smashed

For the pickled saffron shallots:

3/4 cup sherry vinegar

1 tablespoon sugar

Kosher salt

Pinch of saffron

2 large shallots, thinly sliced

For the aioli:

1/4 cup mayonnaise

1 teaspoon harissa (chile paste)

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

For the crispy prosciutto:

1/2 cup canola oil

4 thin slices prosciutto di Parma

For the burgers:

1 1/4 pounds beef chuck roast, cut into 2-inch pieces (or use 1 1/2 pounds ground 80/20 beef chuck and omit the pork fat)

4 ounces pork fat (omit if using ground 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