Heat the olive oil in a large, heavy-based frying pan over high heat.
Add the bacon and cook, stirring, for 2 minutes.
Add the mushrooms and cook, stirring, for 5 minutes or until softened and slightly golden.
Add the garlic and cook for 30 seconds, until fragrant.
Add the chicken stock, thickened cream, pepper and the pasta. Scatter the pasta in the pan and push it down with the back of your spoon so that it is submerged under the liquid.
Reduce the heat to medium–low (so that the liquid is gently bubbling; if it is not hot enough and bubbling, the liquid will not absorb). Cook for 10 minutes, stirring regularly to stop the pasta sticking to the bottom of the pan.
At the end of the 10 minutes, add ½ cup boiling water and stir for 1 minute to help loosen the sauce to your desired consistency.
Turn the heat off. Stir through the spring onion and parmesan and serve.
