For the jowls: Combine jowls, bay leaves, oregano, thyme, peppercorns, kosher salt, pink salt and 3 quarts water in a large soup pot. Bring to a boil, then reduce to a low simmer and cook until the jowls are fork-tender throughout, about 2 hours 30 minutes. Set aside to cool in cooking liquid.
Slice each jowl across the grain into about six 1/4-inch-thick slices.
For the amatriciana sauce: Slice the Pancetta into 1/8-inch-thick slices, then cut the slices into 3/4-inch squares. Set aside.
Heat a large, heavy-bottomed saucepot over medium-high heat and add onions and pancetta. Turn heat to high and cook, stirring occasionally, until well caramelized. Add the tomatoes, red pepper flakes and garlic and stir to mix well. Reduce the heat and simmer for 30 minutes. Remove from heat and keep warm. Season to taste.
Heat a large cast-iron pan over medium-high heat and add the olive oil. Cook until smoking, then add 2 to 3 slices jowl to the pan. (Don't crowd them in the pan; give them room to breathe.) Caramelize both sides of the jowl slices until crisped, then remove them to a paper towel to absorb excess oil. Continue with remaining slices. Arrange the slices on a large platter and spoon a generous amount of amatriciana sauce on top. Sprinkle with pecorino and chopped parsley.
Yield: One 3 1/2- to 4-pound pancetta
Combine kosher salt, sugar and pink salt in a medium bowl and mix well. Roughly chop the rosemary and thyme leaves and mix them into the dry ingredients. Add the peppercorns, red pepper flakes, coriander seeds and garlic and mix well again. Set aside.
Place the pork belly in a shallow plastic bin or on a cookie sheet and rub liberally with the cure; it should have a uniform coating on it, almost as if you'd dredged it. Put the pork belly in a 2-gallon resealable plastic bag and seal it. Refrigerate, flipping the bag every 2 days and working the cure into the meat, for 9 days.
Remove the pork belly from the bag and rinse all the cure off. Use a meat needle to insert a string into one corner of the pancetta. Hang it in the refrigerator to dry for 1 to 2 weeks more. (The pancetta will be ready in 1 week, but an additional week of curing will intensify the flavor.)
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.