Start by cleaning the calamari. Please refer to the video on this page where I show you how to clean a whole calamari.
Chop the tentacles up into small pieces. To a large pot add a drizzle of olive oil and sauté the tentacles until they turn a pinkish color. Removed with the slotted spoon and set aside.
To a large bowl, add the breadcrumbs, grated cheese, fresh parsley, garlic, salt, pepper, the whisked egg, and the cooked tentacles. Mix well to combine then drizzle in about 2 tablespoons of olive oil and continue to mix until the mixture sticks together when you squeeze it with your hands.
Holding the calamari over the bowl, use a spoon or a fork to fill the calamari within 1 inch of the top. Use the back of the spoon or fork to push the stuffing down to the bottom. Do not compact the stuffing too much. Use a toothpick to secure the top so the stuffing doesn't fall out in the cooking process. Do not overstuff the calamari because they will burst while cooking.
To the same part where you cook the tentacles add a little more olive oil and sear the calamari on all sides. Remove from the pot and set aside.
To that same pot, add a little bit more olive oil, garlic, red pepper flakes and parsley stalks. Sauté until fragrant, and then remove the parsley stalks. The glaze the pan with 1/2 cup of white wine, scraping all the bits off the bottom.
Then add in a 28 ounce can of puréed San Marano tomatoes. Rinse out the can by filling it halfway with water and adding that to the pot. Season with salt and pepper to taste and then add the calamari back in.
Cook for 25 to 30 minutes on medium low flame. Stir occasionally to make sure nothing sticks at the bottom. If the sauce has not thickened enough, you can cook it for another 10 minutes on a slightly higher flame, but watch the bottom to make sure nothing is sticking.
If serving with spaghetti, boil 1 pound of spaghetti, remove the calamari from the pot and add the cooked spaghetti to the sauce and mix well. Top with fresh parsley.