Place the chicken thighs in the slow cooker.
In a medium bowl, whisk together the peanut butter, coconut milk, soy sauce, honey, garlic, ginger, and red pepper flakes until smooth.
Pour the peanut sauce over the chicken in the slow cooker, ensuring the chicken is well coated.
Cover and cook on low for 6-8 hours or on high for 3-4 hours, until the chicken is tender and easily shredded.
Once cooked, shred the chicken using two forks and stir it back into the sauce.
Serve the peanut chicken over cooked rice or quinoa, and garnish with chopped green onions and peanuts.