Cook pasta according to packet directions, drain. Toss though a little olive oil to stop the pasta from sticking together then set aside.
In a large pan, heat oil over medium to high heat. Add oyster mushrooms and saute for 1-2 minutes until soft.
Add lime zest, lime juice, smoked salmon pieces, baby spinach leaves and chicken stock to the pan. Stir until baby spinach leaves begin to wilt and the sauce has reduced slightly.
In a separate bowl or jug, add cornflour to milk and whisk until dissolved. Then, slowly pour milk into the pan while stirring continuously.
Finally, add cooked pasta and dill to the sauce. Toss until pasta is evenly coated in sauce and the sauce has thickened.
Divide pasta between bowls and sprinkle with grated pecorino cheese to serve.