Prepare the crockpot by greasing it lightly.
Season the chicken thighs with salt and pepper.
In a skillet, heat olive oil over medium-high heat and brown the chicken thighs.
Transfer the browned chicken thighs to the crockpot.
Add minced garlic, lemon juice, lemon zest, chicken broth, and thyme to the crockpot.
Cover and cook on low for 6-8 hours, or high for 4 hours.
Once cooked, remove the thighs and set them aside.
If desired, thicken the sauce with cornstarch.
Serve the chicken thighs with the sauce poured over.