Prepare the duck: Trim excess fat, rinse, and pat dry. Score the skin lightly.
Season: Rub salt, pepper, and thyme all over the duck.
Stuff: Place orange quarters and smashed garlic inside the cavity.
Layer vegetables: Place sliced onion at the bottom of the crock pot.
Cook: Place the duck on top of the onions, pour chicken stock around it. Cover and cook on low for 7 hours (or high for 4 hours).
Glaze: Mix honey and soy sauce, brush over duck in the last 30 minutes of cooking.
Optional finishing: For crispy skin, broil the duck for 5–10 minutes in the oven.
Serve: Let the duck rest for 10 minutes before carving and serving.