Preheat oven to 180°C (allow 30 minutes cooking per 500g of chicken).
Blend the butter, Swiss brown mushrooms and thyme in a food processor and season generously with salt and pepper.
Gently loosen the skin by pushing your fingers along the surface of the meat around the breast and thighs.
Push the butter under the skin and work the butter as far down under the skin as possible.
Sprinkle the paprika over the skin and rub until evenly coated.
For the stuffing, heat the olive oil in a large frying pan over medium high heat.
Add the chorizo, flat mushrooms and spring onion and cook for 2 minutes, stirring regularly.
Season to taste and remove from the heat.
Push one of the Portabella Mushrooms and chorizo mixture firmly into the cavity inside the chicken, creating pressure so they roast with the chicken juices.
Close up the cavity with the other Portabella Mushroom.
Chop the veggies and place into the base of a baking tray.
Season the veggies with lots of salt and pepper, then drizzle with olive oil and mix together using your hands.
Cook the veggies together with the chicken.
Remove from the oven and serve with stuffing and veggies.