Preheat the oven to 425°F (220°C). Line a large sheet pan with parchment or lightly grease it.
In a large bowl toss the sliced chicken with 1 tablespoon tamari, 1 tablespoon orange juice, and a few grinds of black pepper.
Sprinkle the cornstarch (or arrowroot) over the chicken and toss lightly to coat, then drizzle with 2 tablespoons olive oil.
Spread the chicken in a single layer on the prepared sheet pan and bake for 15 minutes.
While the chicken bakes, whisk the sauce: combine 1/3 cup tamari, 2 tablespoons orange juice, 1/4 cup honey, 2–3 tablespoons chili paste, chopped garlic, and chopped ginger in a bowl.
When the chicken has baked 15 minutes, remove the pan and pour about two-thirds of the sauce over the chicken. Toss to coat, return to the oven and bake another 5 minutes, until cooked through.
Switch the oven to broil and broil the chicken 1–2 minutes until edges char slightly; watch closely to avoid burning. Optionally spoon remaining sauce over the chicken.
Make the yum yum sauce by whisking together 1/3 cup olive oil mayo, 2 tablespoons ketchup, 1 tablespoon Worcestershire sauce, 1 teaspoon seasoned salt, and 1/4 teaspoon cayenne; taste and adjust seasoning.
Assemble bowls by dividing cooked rice among bowls, topping with sliced cucumber, avocado, kimchi, the sauced chicken, green onions if desired, and a handful of fried wontons. Spoon the yum yum sauce over each bowl.