In a medium mixing bowl, whisk together the honey, low-sodium soy sauce, tomato paste, rice vinegar, minced garlic, grated ginger, and chili paste until the sauce is well blended.
Place the chicken thighs in an even layer at the bottom of a 6-quart slow cooker.
Pour the prepared honey garlic sauce over the chicken, making sure all pieces are covered.
Cover the slow cooker and cook on the Low setting for 4 to 5 hours, or on the High setting for 2 to 3 hours, until the chicken is tender and reaches an internal temperature of 165°F (74°C).
Using tongs, remove the chicken from the slow cooker and transfer it to a cutting board. Shred the meat using two forks or slice into bite-sized chunks.
In a small bowl, whisk the cornstarch and cold water together to form a smooth slurry. Pour this mixture into the liquid remaining in the slow cooker and stir well.
Set the slow cooker to the High setting (if not already there), cover, and cook for an additional 15 to 20 minutes until the sauce has thickened into a glossy, sticky glaze.
Add the chicken back into the slow cooker and toss thoroughly to ensure every piece is generously coated in the glaze.
Serve the chicken over a bed of steamed brown or white rice, garnished with toasted sesame seeds and fresh green onions.