In a medium bowl, whisk together peanut butter, soy sauce, honey, vinegar or lime juice, sesame oil, minced garlic, grated ginger, chili flakes, and water or broth until smooth and well combined. If you're using coconut milk for extra creaminess, stir it in at this point.

Place your boneless, skinless chicken breasts or thighs in a slow cooker. Pour the peanut sauce over the chicken, ensuring each piece is thoroughly coated.

Cover the slow cooker with its lid and set it to cook on low for 4 to 6 hours or on high for 2 to 3 hours.

Carefully remove the lid and check for doneness. Using two forks, shred the chicken directly in the slow cooker until fully shredded and coated with the sauce.

Spoon the slow cooker peanut chicken into bowls or over rice, garnishing with crushed peanuts, freshly chopped cilantro, sliced green onions, or sesame seeds.