Whisk the sauce. In a bowl, combine soy sauce, honey, rice vinegar, mirin, garlic, ginger, chicken broth, and sriracha if using. Stir until the honey dissolves.
Load the crockpot. Place chicken thighs in the slow cooker. Pour the sauce over the top, turning the chicken to coat.
Cook low and slow. Cover and cook on Low for 4–5 hours or High for 2–3 hours, until the chicken is fork-tender.
Thighs usually finish closer to 4 hours on Low.
Shred or slice the chicken. Transfer the chicken to a cutting board and shred with two forks or slice into bite-size pieces. Keep warm.
Thicken the sauce. Turn the slow cooker to High. Stir the cornstarch slurry into the hot sauce.
Cover and cook for 10–15 minutes, stirring once, until the sauce becomes glossy and slightly thick. Stir in the toasted sesame oil for aroma.
Combine. Return the chicken to the crockpot and toss with the sauce until generously coated.
Prep the vegetables. While the sauce thickens, steam or sauté your vegetables until crisp-tender. Season lightly with salt if needed.
Assemble the bowls. Add a scoop of rice to each bowl, top with saucy chicken, and add vegetables.
Finish with sesame seeds, green onions, and a squeeze of lime if you like.