Coat a large nonstick skillet with cooking spray; warm over medium heat. Add the chicken thighs and brown, turning once, about 6 minutes; set aside.
Combine the remaining ingredients in a 5- to 6-quart slow cooker; nestle the chicken thighs in the mixture. Cover and cook on low for 7 hours. Yields 1 chicken thigh and about 2/3 cup rice-vegetable mixture per serving.