This is another recipe with a really simple sauce, so before you start any really cooking you want to bring a large pot of salted water to a boil and drop your pasta. Make sure to reserve a cup or so of the cooking water. We started cooking the sauce as the water began to boil and the timing seemed to work out perfectly.
In a large, high-sided pan, melt the butter and olive oil together over medium heat. Toss the bacon into the pan with some pepper and cook until crispy and golden brown, about five minutes. Add the peas to the pan, stirring to combine. Give the peas a minute or two to defrost, then add the creme friache and mint. Stir until the creme friache has melted and coated everything nicely. Season with salt and pepper.
Drain the pasta and add it directly to the sauce pan. Pour the lemon juice over the pasta and stir everything to combine well, making sure the sauce coats each piece of pasta nicely. Finally, mix in the Parmesan cheese. Add some of the cooking liquid to thin out the sauce if desired (this is based totally on personal preference…we didn’t add any water).