Place oil and diced bacon in a 2-quart heavy-bottomed saucepan. Place pan over medium heat and cook, stirring occasionally, until fat is rendered and bacon is crispy. Set aside.
Bring 4 quarts water to a simmer in a stockpot and line a sheet tray with parchment paper.
Combine salt, 1 1/2 cups water and 12 tablespoons butter in a 2-quart saucepan and bring to a boil. Add flour all at once and stir constantly, making sure to not let the mixture stick to the bottom of the pan. Stir until a dough ball forms. Transfer dough to the bowl of a stand mixer fitted with the paddle attachment. With the motor running on low, add Gruyere, Dijon mustard and tarragon and mix until well incorporated. With motor still running, add eggs one at a time, making sure each egg is incorporated before adding another. Transfer dough to a medium pastry bag fitted with a large metal tip.
Slowly pipe dough into boiling water, using a paring knife to slice off into 3/4-inch pieces. (Work in batches.) When gnocchi float, transfer to lined sheet tray and chill until cold.
Heat 2 tablespoons butter in a saute pan until hot and bubbly. Add gnocchi to pan and saute until browned. Add cooked, cubed bacon and stir.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.