Cook the spaghetti according to package instructions until al dente. Reserve 1 cup of pasta cooking water, then drain the pasta.
While the pasta is cooking, heat olive oil in a large skillet over medium heat. Add pancetta and cook until crispy, about 5 minutes. Add garlic and cook for another 30 seconds until fragrant.
Add the peas to the skillet with the pancetta and cook for 2 minutes, then remove from heat.
In a bowl, whisk together the eggs, Parmesan, Pecorino Romano, salt, and pepper.
Add the drained spaghetti to the skillet with pancetta and peas. Toss to combine. Slowly pour the egg mixture over the pasta, stirring quickly to create a creamy sauce.
If the sauce is too thick, add reserved pasta cooking water a little at a time until the desired consistency is reached.
Serve with extra cheese and fresh parsley for garnish.
Notes
Make Ahead: While the carbonara sauce should be prepared fresh, you can cook the pancetta and peas ahead of time and refrigerate.
Customizing the Flavor: Add a pinch of red pepper flakes for heat or a squeeze of fresh lemon juice for a zesty twist.
Serving Suggestions: Serve the spaghetti carbonara with a side salad, crusty bread, or a light soup for a complete meal.
Storage Tips: Store leftovers in an airtight container in the fridge for up to 2 days. Reheat gently, adding a splash of water to loosen the sauce.