Prepare the inside of your slow cooker with nonstick cooking spray or a drizzle of olive oil to prevent sticking.

Place the boneless, skinless chicken breasts or thighs in a single layer at the bottom of the slow cooker.

In a medium mixing bowl, whisk together the honey, Dijon mustard, yellow mustard, minced garlic, olive oil, chicken broth, salt, and pepper until smooth.

Carefully pour the honey mustard mixture over the chicken, ensuring each piece is well coated.

Cover your slow cooker and set it to cook on LOW for 6-7 hours or on HIGH for 3-4 hours.

If you prefer a thicker sauce, mix cornstarch with an equal amount of water and stir it in during the last 10-15 minutes of cooking.

Once cooked, return the tender chicken to the sauce, coating it well. Serve warm, garnished with fresh parsley.