In a large frying pan heat olive oil and butter on medium to high heat. Add onion, mushrooms, pancetta and peas and cook until mushrooms are soft and pancetta is crispy, stirring the whole time. Now add the coffee and cook for 5 to 10 minutes and then turn down heat to low.
In a bowl, combine eggs and cream and whisk together, season with salt and pepper.
Once pasta is cooked, strain and then add to pan. Turn heat off.
Pour in egg and cream mixture and stir through pasta. The heat from the pasta will cook the egg and also heat the cream. Stir well.
Serve pasta topped with shaved parmesan and grated nutmeg.