Combine orange rind, tarragon and butter in a small bowl until well combined. Gently pull skin away from the chicken breast and stuff with 2 tablespoons of orange butter, reserving the remaining mix. Place in a baking paper-lined roasting dish, drizzle with olive oil and bake for 15-20 minutes or until cooked to your liking. Remove chicken from pan and allow to rest. Reserve pan juices.
Cook pumpkin in a medium saucepan half filled with boiling water for 7-10 minutes or until tender. Drain well, return to saucepan and mash. Add butter, season with salt and pepper and mix to combine.
Heat a medium frying pan over a medium heat, add pan juices and onion and panfry until golden. Add orange juice and honey and reduce by a quarter. Add remaining orange butter and stir until butter has melted.
To serve, arrange a spoonful of pumpkin mash in the centre of a serving plate, top with chicken and drizzle with orange sauce. Serve with green beans on the side.