Bring a large pot of salted water to boil and cook the pasta to packet instructions. Add the frozen peas for the last minute of cooking.
Meanwhile, melt the butter in a large frying pan over medium heat and add the bacon. Cook until just turning crispy then turn the heat to the lowest setting.
Drain the pasta and peas, reserving a cup of the pasta cooking water. Or use a spider skimmer to scoop straight from the pan.
Add the peas and pasta to the pan with the bacon and toss together. Add the cheese with 2-3 tablespoons of pasta water and stir well until the cheese has melted and created a silky sauce with the butter, bacon fat and pasta water. Add another tablespoon of butter if desired and stir in more pasta water until the sauce reaches your perfect consistency.
Season with a grind of black pepper to taste, and garnish with extra grated cheese if desired.
Notes
I like to use a mild and creamy cheese like Gouda, Emmental or Jarlsberg for this pasta dish, but feel free to use any cheese which melts well. I have used parmesan and pecorino to great effect, and cheddar or grated mozzarella would also work.