Preheat oven to 350 degrees F (175 degrees C). Line a baking sheet with aluminum foil.
Arrange pancetta on the prepared baking sheet.
Bake in the preheated oven until pancetta is crispy, about 20 minutes. Remove pancetta to a cutting board and chop. Pour the drippings on the baking sheet into a skillet; add olive oil to skillet.
Heat drippings and olive oil in the skillet over medium heat; cook and stir shallots, asparagus, tarragon, and pancetta in the hot drippings-oil mixture; season with salt and pepper. Cover skillet and cook until asparagus is tender, 15 to 20 minutes.