Pretzel Tonkatsu Burger (Japanese)

Amy Thielen combines her Midwestern roots with a Japanese fast-food favourite for this crunchy burger coated in pretzel and panko breading, fried in peanut oil, and topped off with a sweet-savoury sauce made from browned butter, ketchup, sake, and a dash of fresh ginger. Serve it with a cold Swiss chard dish as a side.

Burger:
1 lb quality ground beef, not lean
2 eggs
1 cup pretzel meal, finely crushed (~ 5 oz pkg pretzels, ground to a powder in a food processor)
¾ cup panko (2½ oz)
½ tsp. sea salt
black pepper, freshly ground
4 cups peanut oil, for frying

Tonkatsu Sauce:
2 Tbsp. butter (1 oz)
⅓ cup ketchup (3½ oz)
1 (2") piece fresh ginger (1¼ oz)
2 Tbsp. sake (1 oz)
black pepper, freshly ground

Make the Tonkatsu Sauce:
Grate the fresh ginger into a small dish. Squeeze with your fingers to extract 1 Tbsp. of liquid ginger juice (or, if you like, squeeze it through a moist paper towel). Heat a small sauté pan over medium-high heat and add the butter. Cook until it browns lightly, about 5 minutes, then add the ketchup. Cook, stirring, until it thickens and loses its raw taste, about 1 minute. Off heat, add the ginger juice, sake and black pepper to taste and stir to combine. Set aside.

For the Tonkatsu:
Lightly season the ground beef with salt and black pepper, then shape it into four 4 oz pucks about 3½" wide and 1" thick. Season both sides with more salt and pepper to taste. Prepare two bowls for breading: one with beaten egg, the second with the mixture of pretzel meal and panko. Season the panko mixture with ½ tsp. salt and ¼ tsp. of pepper. Double-bread the patties: drop each burger into egg, and finally drop into the pretzel/panko mixture, pressing gently on the patty to make the coating adhere, and repeat: drop again into the egg and the panko mixture. Set them on a plate.

Pour ½" of oil into a heavy cast-iron skillet and preheat over medium-high heat. When the oil registers 350°F on a deep fry thermometer, carefully add the tonkatsu patties, leaving a little room around them. Fry quickly, about 2 minutes per side, until evenly browned and crispy. Blot on a paper towel-lined plate and serve with a ½ cup of marinated greens and a dollop of tonkatsu sauce.

Makes 4 servings.