Mince the garlic, scallions and ginger, combine with the soy sauce, sugar, sesame oil, chili flakes, black pepper and salt. Stir to dissolve the sugar and salt. Set aside half of this mixture.
Combine half of the soy mixture with the ground beef and mix well. Divide and shape into 4 burger patties. Press the sesame seeds into the patties to give them a good crust of sesame seeds.
Heat a large sauté pan over medium heat. Once hot, remaining sesame oil to crisp the sesame seeds. Carefully place the burgers in the hot oil. Cook for about 5 minutes per side or until the burgers have reached a minimal internal temperature of 160°F. Reduce the heat if the sesame seeds get too brown.
Meanwhile, thinly slice the cucumber and onion and place in a large bowl with the cilantro leaves. Add rice vinegar to the reserved soy mixture and dress the cucumber salad with this dressing.
Split and toast the hamburger buns. Assemble the burgers with the burger patty on the bottom bun, then some of the cucumber salad then the top bun. Serve extra salad on the side.
Approximate Nutritional Information (Per serving):
Calories 620, Fat 36g, Sat. Fat 10g, Trans Fat 1g, Cholesterol 105mg, Sodium 1120mg, Total Carbohydrate 36g, Fiber 3g, Sugars 9g, Protein 38g
ALLERGEN CALLOUTS: Tree Nut-Free, Peanut-Free, Egg-Free, Dairy-Free