In a large pot or Dutch oven over medium heat, cook the chopped bacon until crispy, about 6-8 minutes. Remove bacon with a slotted spoon and set aside, leaving about 2 tablespoons of bacon fat in the pot.
Add the diced onion to the pot and sauté in the bacon fat for 3-4 minutes until softened. Add garlic and cook for another minute until fragrant.
Add the dry pasta, chicken broth, and heavy cream to the pot. Stir well and bring to a boil.
Reduce heat to medium-low, cover, and simmer for 12-15 minutes, stirring occasionally to prevent sticking, until pasta is al dente and most of the liquid is absorbed.
Stir in the frozen peas and cook for 2-3 minutes until heated through.
Remove from heat and stir in the Parmesan cheese and half of the cooked bacon. Season with salt and pepper to taste.
Serve immediately, topped with remaining bacon and fresh parsley if desired.