Preheat the oven to 180 degrees C. Heat 1 tablespoon of the oil in a large, deep frying pan, add the mushroom and spring onions and sauté over a moderate heat for 5 minutes until the mushroom is tender. Stir in the spinach and cook, stirring, for 2 minutes, until wilted.
Transfer the vegetables to a large bowl, using a slotted spoon to drain off any excess moisture from the spinach. Add the breadcrumbs, parmesan and salt and pepper and toss well.
Pound the chicken flat and thin between two sheets of plastic wrap. Spread 2 tablespoons of the spinach filling onto each piece of chicken, to about 1cm from the edges. Then, starting at one of the narrower ends, roll up and secure the roulades with cocktail sticks or kitchen string.
Clean the frying pan, then add the remaining oil and set the pan over a high heat. Add the roulades, seam side down first, and cook for 6 minutes, or until browned all over.
Place the roulades in a shallow ovenproof dish and pour in the hot stock. Cover and bake for 15–18 minutes, or until the chicken is cooked through.
To serve, remove the cocktail sticks or string from the roulades and cut the chicken diagonally into 1 cm slices. Serve hot, drizzled with the cooking juices.