Preheat the oven to 350°F/180°C.
Heat oil in a large oven-safe skillet or Dutch oven over medium-high heat. Sear chicken drumsticks on both sides until golden. Remove from the pan.
Add onion to the same pan with a pinch of salt and cook 7–10 minutes until starting to brown. Add fennel and cook until lightly caramelized.
Return chicken to pan, nestling between onions and fennel. Scatter lemon slices on top. Mix stock, honey, paprika, and garlic, then pour over chicken. Cover with parchment and foil, simmer on medium heat for 10–15 minutes.
Transfer pan to oven. Bake covered for 10 minutes, then uncovered for 25–30 minutes, occasionally spooning sauce over chicken. Chicken should be tender and golden.
Remove from the oven, sprinkle with cilantro, adjust salt if needed, and serve with rice.