Ko Burger Recipe

Combine sauce ingredients

In a small bowl whisk together ketchup (0.25 cups), mayonnaise (0.1 cups), yellow mustard (1 tsp), sweet pickle relish (1 tsp), white vinegar (0.5 tsp), and sugar (0.25 tsp) until smooth. Adjust seasoning to taste. Set aside in refrigerator while you prepare other components.

Cut and soak potatoes

Peel (optional) and cut russet potatoes into 1/3-inch to 1/2-inch fries. Place cut fries in a large bowl and cover with 4 cups cold water. Soak at least 30 minutes (up to 2 hours) to remove surface starch.

Dry and toss with cornstarch

Drain the potatoes and pat thoroughly dry with clean kitchen towels or paper towels. Toss dried fries with 1 tablespoon cornstarch until evenly coated — this helps achieve a crisp exterior.

Fry until golden

Heat about 1 cup vegetable oil in a heavy skillet or deep pan over medium-high heat to 325°F (if you have a thermometer). Fry the fries in batches for 3–4 minutes until soft but not browned. Remove and drain on paper towels. Increase oil temperature to 375°F and return fries in batches, frying 2–3 minutes until golden and crisp. Drain on paper towels and immediately season with 1 tsp kosher salt.

Toast buns

Heat a skillet over medium heat. Spread butter on cut sides of 4 hot dog buns and toast, buttered-side down, until golden, about 1–2 minutes. Remove and keep warm.

Cook dogs

Using the same skillet, add a small splash of oil if needed and sear the hot dogs over medium-high heat, turning occasionally, until nicely browned and heated through, about 4–5 minutes. Alternatively, simmer in water for 3–4 minutes then char on a hot griddle for 30–60 seconds per side.

Assemble hot dogs

Place each hot dog in a toasted bun. Top with 1 tablespoon yellow mustard, roughly 1 tablespoon diced onion, and 1 tablespoon relish (adjust to taste). Serve immediately.

Portion the beef

Divide 1.25 lbs 80/20 ground beef into 4 equal portions (~5 oz / 140 g each). Gently roll each portion into a loose ball — do not overwork the meat. Season both sides lightly with salt and black pepper just before cooking.

Preheat griddle

Preheat a heavy cast-iron skillet or flat griddle over high heat until very hot. Add 1 tablespoon vegetable oil and spread to coat.

Smash and sear

Place a beef ball on the hot surface. Immediately press down firmly with a heavy metal spatula or burger press to form a thin patty (about 3–4 inches wide). Hold the press for 10–12 seconds to maximize contact. Cook without moving for 2–2.5 minutes until edges are deeply browned and crispy.

Flip, cheese, and finish

Flip the patty, quickly add a slice of American cheese, and cook another 45–60 seconds until cheese melts and the patty is done. Repeat with remaining patties, working in batches so the griddle stays hot. If needed, wipe excess fond and re-oil between batches.

Toast buns and assemble burgers

While finishing the last patties, split and toast burger buns on the griddle cut-side down until golden, about 30–45 seconds. To assemble: spread about 2 tablespoons KO burger sauce on each bottom bun, place a cheesy smash patty, add a few pickle slices and a sprinkle (about 1 tablespoon) of diced onion, then top with the bun crown. Serve immediately with fries and hot dogs.