For the sauce, whisk rice vinegar, sriracha, honey and mustard in a medium measuring cup until smooth; set aside.
Cut chicken thighs into small square pieces. (You should be able to get 6-8 pieces out of each thigh.) Put the chicken in a large mixing bowl and season with paprika, granulated garlic, granulated onion, salt and olive oil. Thread the chicken on skewers and grill over high heat until thoroughly cooked and the chicken has some nice grill marks on it, usually for about 7-8 minutes each side. (You can also use a stove-top griddle). While grilling the chicken, lightly brush the sauce onto the chicken skewers keeping them sauced and juicy.