In a small blender or food processor, combine all sauce ingredients. Season with ½ teaspoon salt and ¼ teaspoon pepper, or to taste. Blend until smooth. Cover and refrigerate until ready to use.
Preheat oven to 425°F. Line a large sheet pan with foil.
In a small bowl, combine all the seasoning blend ingredients. Season with salt and pepper to taste (I add 1 teaspoon salt and ¾ teaspoon pepper). Whisk to combine.
Pat chicken thighs dry with a paper towel. Rub or use a pastry brush to evenly coat each piece with the seasoning mix. Make sure to use every bit of the seasoning mix.
Lay the thighs flat on the prepared sheet pan, spacing them out to ensure they aren't bunched together. Bake for 15 minutes, then remove the pan from the oven.
Move the oven rack to about 8 inches from the heat source and switch the heat to broil. Immediately return the tray to the oven and broil for 7-10 minutes until nicely blackened and caramelized. (See Note 2). Let rest 5-10 minutes tented with foil then slice or chop.
Divide cooked white rice evenly among bowls. Top with chicken, black beans, mango, avocado, cilantro, or any other desired toppings. Add a generous scoop of sauce on top and enjoy!