Prepare the Crockpot: Lightly grease the inside of your 5-6 quart slow cooker with a little oil or cooking spray. Place the thinly sliced red onion in an even layer on the bottom, then arrange the chicken breasts on top.

Make the Peanut Sauce: In a medium bowl, combine all the sauce ingredients: peanut butter, coconut milk, stock, soy sauce, honey, rice vinegar, lime juice, ginger, garlic, sesame oil, and red pepper flakes (if using).

Whisk Until Smooth: Whisk the sauce vigorously until it is completely smooth and well combined. The peanut butter can be a bit stiff at first, but keep whisking and it will loosen up into a creamy consistency.

Combine and Cook: Pour the peanut sauce evenly over the chicken breasts in the crockpot, making sure to coat them well.

Set the Timer: Cover the crockpot and cook on LOW for 4-5 hours or on HIGH for 2-3 hours. The chicken is done when it's cooked through and tender. What works best for me is the LOW setting, as it keeps the chicken extra moist.

Shred the Chicken: Once cooked, remove the chicken breasts from the slow cooker and place them on a cutting board. Use two forks to shred the meat. It should come apart very easily.

Combine and Absorb: Return the shredded chicken to the slow cooker and stir it into the peanut sauce. Let it sit on the 'keep warm' setting for 10-15 minutes to allow the chicken to soak up all the flavour of the sauce.

Serve and Garnish: Serve the Thai peanut chicken hot over steamed rice or noodles. Garnish generously with chopped fresh coriander, roasted peanuts, and spring onions. A final squeeze of lime juice just before eating really brightens everything up.