In a bowl, combine all the ingredients except the oils. Whisk in the sesame oil and then the peanut oil. Taste and add a bit more salt if you like. Refrigerate for up to ten days.
Mix the five-spice powder, the 1 Tbs. sugar, the garlic powder, and the salt in a small bowl. In another bowl, mix the soy sauce, vinegar, sesame oil, red pepper flakes, and remaining 1 tsp. sugar.
Put the chicken in a shallow pan, drizzle with the vegetable oil, and toss to coat evenly. Sprinkle the spice mixture over the chicken; toss and rub to coat thoroughly.
Prepare a hot charcoal fire or heat a gas grill with all burners on medium high for 10 min. Clean the hot grate with a wire brush and then lubricate it with an oil-soaked paper towel. Put the chicken on the grate and grill (covered on a gas grill or uncovered over a charcoal fire) until one side has dark grill marks, 5 to 6 min. for large thighs or 4 to 5 min. for medium and small thighs. Turn and continue to grill until well marked on the other sides and cooked through, 5 to 6 min. longer for large thighs or 4 to 5 min. for medium and small thighs.
Move the thighs to a serving dish. Drizzle with about half of the soy mixture, sprinkle with the cilantro, and toss to coat. Let rest 4 to 5 min., tossing once or twice. Serve hot, warm, or at room temperature, with the remaining soy mixture passed at the table.
In a bowl, combine all the ingredients except the oils. Whisk in the sesame oil and then the peanut oil. Taste and add a bit more salt if you like. Refrigerate for up to ten days.
In a small, dry saucepan, toast the red pepper flakes over high heat until fragrant, 1 to 2 minutes. Add the salt, sugar, and rice vinegar; cook over medium-low heat until the salt and sugar are dissolved. Stir in the garlic. Remove the sauce from the heat and let cool completely.
