Bring a large pot of water to a boil, salt it, add the pasta and cook until al dente. Drain, reserving 1 cup of the cooking water.
While the pasta is working, in a deep skillet with a tight-fitting lid, heat the EVOO, 2 turns of the pan, over medium heat. Add the pancetta (or bacon) and cook until the fat renders, 2 to 3 minutes. Add the onion, garlic and chile; season with pepper. Cover and cook, stirring, for 5 minutes. Stir in the vodka and reduce by half. Stir in the tomatoes and basil and bring to a simmer. Stir in the heavy cream and bring to a simmer.
If using fresh peas, stir them into the sauce (if using frozen peas, wait to add them with the cooked pasta in Step 3). Add the mussels, cover and cook until they open, 7 to 10 minutes. Discard any unopened shells.
Add the pasta to the mussels, adding some of the reserved cooking water as needed to thin the sauce. Toss to combine. Serve the mussels and pasta with crusty bread and cheese, if desired.