Whisk together the tomato paste, rice wine vinegar, honey, and soy sauce until smooth.
1-1/2 tablespoon tomato paste, 1-1/2 tablespoons rice wine vinegar, 1-1/2 cups honey, 3/4 cup soy sauce
Add in the onions, peppers, and minced garlic. Add red pepper flakes, if desired.
3/4 cup diced onion, 1/2 cup diced yellow pepper, 1-1/2 tablespoons minced garlic, 1/2 tablespoon red pepper flakes
Season the chicken breasts with salt and pepper and add to the slow cooker.
Salt and pepper, 6 boneless skinless chicken breasts or boneless chicken thighs
Set the slow cooker on low to cook for 5 hours.
30 minutes before serving, add the carrots and remove the chicken. Use two forks to pull it apart. Return to the slow cooker.
3 large carrots
In a small dish, make a slurry with cornstarch and water. This will thicken the sauce.
6 teaspoons cornstarch
Turn the heat up to high for 30 minutes.
Serve over rice with a garnish of sesame seeds and scallions if desired.
Sesame seeds and Scallions for garnish