In a large skillet over medium-high heat, heat oil. Season chicken thighs with salt and pepper and cook, turning halfway through, until golden brown, about 3 minutes per side. Transfer to a slow cooker.
In a small bowl, whisk garlic, ketchup, soy sauce, honey, lime juice, sriracha, and ginger. Pour sauce over chicken and toss until coated.
Cover and cook on Low for 5 to 6 hours or on High for 2 hours, until an instant-read thermometer inserted into thickest part of chicken registers 165°.
Divide rice among plates. Top with chicken, then spoon sauce over.
