Preheat the oven to 400 degrees F. Heat 2 tablespoons olive oil in a large skillet over medium-high heat. Add the shallot, garlic and fennel seeds and cook until the shallot is slightly soft, 2 minutes. Stir in the rosemary, thyme, red pepper flakes and 1/4 teaspoon salt and cook 1 more minute. Remove from the heat and let cool slightly.
Lay the turkey, skin-side down, on a cutting board. Cover with a sheet of plastic wrap and pound lightly with a meat mallet until it's about 8 by 12 inches and 1/4 inch thick. Remove the plastic wrap and season with 1/4 teaspoon each salt and pepper.
Cut four 12-inch pieces of kitchen twine. Spread the garlic mixture evenly over the turkey. Arrange the pancetta on top in an even layer, then sprinkle with the parsley. Starting from a long side, roll up the breast and tie gently with the twine. Brush with the remaining 1 tablespoon olive oil and season with salt and pepper.
Put the stuffed turkey breast on a rack in a roasting pan and pour 1 cup water into the pan. Roast until the skin is golden, about 40 minutes. Increase the oven temperature to 425 degrees F and roast until the skin is crisp and a thermometer inserted into the thickest part of the turkey registers 155 degrees F to 160 degrees F, about 10 more minutes.
Transfer the turkey to a cutting board and let rest at least 30 minutes before slicing. (If making ahead, let cool completely, then wrap in plastic wrap, unsliced, and refrigerate up to 2 days.) Make the sandwiches: Drizzle the cut sides of the rolls with olive oil. Sandwich the provolone and turkey in the rolls and drizzle the meat with any pan drippings.
Stand the corn upright in a large bowl when slicing off the kernels so they don't scatter all over the counter.