optional fresh pea pods, split in half lengthwise, for garnish if desired
Lightly butter the insides of 6 ramekins that are 5″ in diameter and 1″ tall. Place ramekins on a large rimmed pan and set aside. Place oven rack in upper third of oven. Preheat to 350°F.
In medium-size non-stick skillet over medium heat, cook pancetta until chewy-crisp, stirring regularly. Remove pancetta from skillet to a paper towel-lined plate. Discard all but 1 tablespoon of fat from the skillet, and then add shallot to skillet and cook until softened, stirring often. If the shallot starts to brown before it is softened, turn down the heat a bit. Remove shallot to a plate.
In a medium bowl, whisk eggs, cream, mustard, parsley, salt, and pepper. Divide mixture evenly among the 6 ramekins. Reserve a bit of the pancetta for the tops of the eggs, and then divide the remaining pancetta among the 6 ramekins. Reserve a bit of the peas and cheese for the tops of the eggs, and then divide the remaining among the 6 ramekins. Give the mixture in each ramekin a little stir with a spoon and then place pan of ramekins in the oven. Bake for 15 minutes.
Remove pan of ramekins from oven and top each ramekin with reserved cheese, then reserved pancetta and peas. Add a split fresh pea pod, if desired. Return pan of ramekins to oven and bake for an additional 5 minutes or so. You want the eggs to be just softly set and the cheese on top melted. Garnish with freshly ground black pepper and a bit of chopped parsley. Let sit for a few minutes before serving.