Fill a large pot with 4 cups of water and bring it to a rolling boil. Add a generous pinch of salt, then toss in your spaghetti or fettuccine. Cook according to package instructions until al dente (about 8-10 minutes). Stir occasionally to prevent sticking.

In a large skillet, place the chopped bacon over medium heat. Sizzle until crispy, about 5-7 minutes. Remove the bacon from the skillet and place it on paper towels to absorb excess grease.

Using the bacon drippings in the same skillet, add the finely diced onions. Sauté for about 3-4 minutes until softened and golden. Add the minced garlic and cook for an additional minute. Be careful not to burn the garlic.

In a mixing bowl, whisk together the eggs, heavy cream, and freshly grated Parmesan cheese. Add the crushed red pepper flakes and black pepper. This creamy mixture will create the sauce that binds everything together.

Drain the cooked pasta, but don’t rinse it. Immediately add the hot pasta to the skillet with the sautéed onions and garlic. Turn off the heat and quickly pour the egg and cheese mixture over the pasta, stirring vigorously. The heat from the pasta will cook the eggs gently and create that creamy sauce. Add the crispy bacon back into the mix.

If using peas, add them now. Stir until everything is well combined and heated through.

Plate your delicious carbonara and garnish with additional Parmesan cheese and freshly ground black pepper.