In a medium skillet, cook pancetta over medium-high heat until crispy, about 8 minutes. Using a slotted spoon, transfer pancetta to a plate lined with a paper towel.

Cook shallot in pancetta fat until soft and slightly caramelized, about 10 minutes. Add 1/4 water as needed to prevent sticking. (Alternately you can clean out the skillet with a paper towl and cook the shallots in olive oil.)

In a medium bowl, whisk 2 ounces of Stilton, mayonnaise, canola oil, red wine vinegar and lemon juice until smooth. Season with salt and pepper. If too thick, add 1 tablespoon of water and whisk.

Cut 1/2 head of iceberg lettuce in half and put on two plates. Spoon 2 to 3 tablespoons of dressing over lettuce and divide pancetta, shallot, remaining 2 ounces of Stilton and parsley between lettuce. Serve remaining dressing on the side.