Add pancetta to a cold pan and raise the heat to medium. Slowly fry the pancetta until it is golden brown, about 8-10 minutes. Then use a slotted spoon to remove the pancetta from the pan. Drain the oil but leave about 3 tablespoon in the pan.
Bring a large pot of water to a boil. Salt the water then add the pasta. Cook for 2 minutes less than stated on the box.
Saute the garlic in the oil for 30 seconds then add the peas to the pan. Saute for a few minutes until the peas soften up and then add a ½ cup of pasta water. Pour in the fusilli and mix well.
Remove the pan from the heat and add another ½ cup of pasta water and the pecorino romano. Stir vigorously until everything is combined. Add the pancetta back into the pasta. Season with pepper. Combine and serve.
Notes
Fry pancetta from a cold pan. This will help render the fat and make the pancetta golden brown and crispy.
When combining the pasta water and pecorino romano, make sure to remove the pan from the heat so that the cheese doesn't stick to the bottom of the pan.