Start by adding the mushrooms and sun-dried tomatoes and oil into a frying pan over a high heat. Leave to brown for 4 minutes, then stir and continue to fry for a further 4 minutes.
During this time, add the rigatoni to heavily salted boiling water. Set your timer to the packet time minus 2 minutes.
When your mushrooms have browned and the sun-dried tomatoes are getting crispy, remove a third to have as a garnish. Reduce the heat to low and add the garlic and lemon zest.
Fry for 2 minutes, then add the creme fraiche. Once heated through, slowly add two ladles of pasta water whilst continuously stirring. Season with salt and lots of pepper, then add the spinach.
Once the spinach has wilted, transfer the al dente pasta into the sauce with a few ladles of pasta water. Add the pecorino at this stage and stir to combine, cook over a low heat.
Add pasta water or cook off as necessary until you have a thick and creamy sauce (this should only take a minute or two). Season with lots of pepper and top with the reserved mushrooms and sun-dried tomatoes. Enjoy!