Preheat the oven to 350F.
Rinse the outside and the cavity of your whole chicken and pat dry.
Stuff the chicken cavity with the onion, garlic cloves, and sprig of fresh rosemary.
Place the chicken, breast side up, in the dutch oven. Drizzle the melted butter over the surface of the chicken.
Combine the smoked paprika, black pepper, and mineral salt in a small bowl. Mix well and sprinkle over the surface of the chicken, taking care to get the wings and legs as well.
Place the lid on the dutch oven and place into the preheated oven.
Bake for 70-90 minutes with the lid on, depending on the size of the chicken. If the chicken is on the smaller end, bake for 70, for chickens close to 5lbs, bake for 90 minutes.
Remove the chicken from the oven. Increase the temperature to 425F and remove the lid from the dutch oven. Baste the chicken with the drippings. Once the oven reaches the new higher temperature, place the chicken back in the oven and bake for an additional 30 minutes, or until there is an internal temperature of at least 165F in all parts.
Remove the chicken from the dutch oven to a plate and serve! You can also serve directly in the dutch oven if you have a sturdy heatproof trivet for your kitchen table.