Begin by patting dry the boneless chicken thighs with paper towels; this ensures a crispy exterior when cooked. In a small bowl, mix cornstarch with kosher salt and freshly ground black pepper, then coat each chicken thigh evenly with this mixture.

Heat a tablespoon of oil in a skillet over medium-high heat until it shimmers. Carefully place the coated chicken thighs in the hot oil, frying for 5 to 7 minutes on each side until golden brown.

Remove the chicken from the pan and set aside. In the same skillet, lower the heat to medium, adding unsalted butter until melted. Stir in soy sauce, dark soy sauce, honey, five-spice powder, and freshly grated garlic. Allow to simmer for about 5 minutes until it thickens slightly.

Return the fried chicken thighs to the skillet with the simmering glaze. Gently turn the chicken to coat each piece well in the sauce. Cook for another 2 minutes, letting the chicken absorb the flavors of the soy glaze.

Remove the pan from heat and transfer the soy glazed chicken onto a serving platter. Garnish with sesame seeds and chopped scallions for added flavor and color. Serve over rice with steamed vegetables.