Stir the Greek yogurt, 1 tbsp cider vinegar, Dijon, 1/2 tsp salt and 1/4 tsp pepper together in a 3-quart / 2.8 L bowl. Add the cabbage, carrot and green onions, toss until every shred is coated, and refrigerate while you cook.
Cut the chicken thighs into 2.5 cm / 1-inch pieces and pat dry. Toss with the cornstarch, 1 tsp salt, paprika, garlic powder and 1/2 tsp pepper until lightly dusted. In a small bowl, stir the honey, hot sauce, remaining 1 tbsp cider vinegar and pepper flakes.
Rinse the rice in a fine-mesh sieve until the water runs mostly clear. Combine with the water and 1/4 tsp salt in a 2-quart / 1.9 L saucepan and bring to a boil over high heat, about 3 minutes. Cover, drop to low and cook 17 minutes, then take it off the heat and keep the lid on for 10 minutes. Fluff with a fork.
While the rice simmers, heat 1 tbsp oil in a 30 cm / 12-inch cast-iron skillet over medium-high until it shimmers. Add half the chicken in a single layer and cook undisturbed for 3 minutes. Stir and cook 3 to 4 minutes more, until deep golden and a piece reads 165 F / 74 C. Move to a plate.
Add the remaining 1 tbsp oil and cook the second half of the chicken the same way. Return the first batch to the skillet.
Reduce the heat to low, add the butter and the honey mixture, and stir for 1 to 2 minutes until it bubbles gently, turns glossy and clings to the chicken. Honey scorches fast, so if the pan smells bitter or the glaze turns dark brown, pull it off the heat right away and stir in a splash of water.
Divide the rice among 4 bowls, top with the chicken and any glaze left in the pan, and add the slaw alongside. Serve right away while the chicken is hot and the slaw is cold.